App Layering

What’s new

Citrix delivers new features and improvements to Citrix App Layering users when they are available. New releases provide more value, so there’s no reason to delay updates.

This article covers new and enhanced features, along with the fixed issues in this release.

For the latest App Layering requirements and supported platforms, see System requirements.

App Layering 2403 (This release)

This release contains the following new features:

  • Citrix Hypervisor rebranded to XenServer

In line with our latest rebranding strategy, we’ve updated all instances of Citrix Hypervisor to XenServer.

  • OS Machine tools update

The OS Machine tools are now updated to include automatic cleanups of empty INF folders that can cause performance counter rebuild failures. You must create a new revision of your OS layer and apply the OS Machine Tools to the layer.

Note: Don’t run setup_x64.exe on an OS revision. The application is only needed before importing an OS into the elm, and running it on an OS revision might cause unknown issues.

  • Layer creation tasks display more information about the packaging machine

The action required state of layer creation tasks now include more information about the packaging machine than just the VM name when using offload compositing. For most connector types, the additional information is the machine’s IP address.

  • For Nutanix AHV connector types, a link to the packaging machine in the Nutanix Prism UI is displayed.

  • Azure Deployment connector types allow custom information to be provided through the ARM templates. For more information, see Machine Output.

  • New Connector - Windows File Share

The Connectors UI now includes Windows File Share. This connector allows the user to publish a disk to a file share, leveraging an existing offload-enabled connector configuration.

For more information, see Windows File Share.

  • User Personalization Layer - User Layer/UPL space reclamation

Previously, Windows used the unused blocks on a disk first, requiring a large amount of space on the backend file server. By using the new VHDX space reclamation process, the user layer VHDX files are automatically optimized every time the user logs off.

For more information, see User Layer/UPL space reclamation.


  • The Builtin AppV apps are not working with the PVS EL-enabled images. [ALHELP-1717]

  • The PVS Connector publish fails if the share path has a trailing backslash. [UNI-89881]

  • When creating an OS layer from a XenServer gold VM with custom BIOS strings, the ImportOsLayer.ps1 script fails to determine the hypervisor type and fails with the following error: Offload Compositing is not supported on this hypervisor yet The hypervisor type can now be explicitly specified through the -HypervisorType parameter to avoid this issue.[UNI-90521]

App Layering 2312

This release contains the following new features:

  • New and improved Nutanix AHV connector. When you create and manage the Nutanix AHV connector in App Layering, you can now experience the new UI with the modernized Hypervisor support. For more information, see Nutanix AHV connector. This release also introduces Offload Compositing support for layers and image templates in Nutanix AHV. Modern virtualization technologies such as UEFI, vTPM, and Secure Boot are now available with Offload Compositing. For more information, see About Offload Compositing.

  • New approach to override file exclusion. You can now override file exclusions by updating the Gold Image tool to introduce and accumulate default exclusions for the App Layer file system. For more information, see Default exclusions.


  • The HKLM\Software\Wow6432Node\Citrix\PortICA\Policy\Session\PolicyInputValues and HKLM\SOFTWARE\Citrix\VirtualDesktopAgent\Policy\Session\PolicyInputValues keys do not have their values or subkeys persisted between logins. [UNI-89899]

  • When you publish an image with App Layering version 2306, you are unable to see the new image tools, like AppRulesCompare, on the image. [UNI-89936]

  • A login or logout failure might occur when FSLogix uses Cloud Cache locations for profile or ODFC containers along with App Layering Elastic Layers. A pop-up screen displays login failures and a frozen logout screen displays logout failures. FSLogix log files located at c:/ProgramData/FSLogix/Logs/Profile/Profile-YYYYMMDD.log also display the following error message for login failures: "ERROR:00000005 Access is denied" errors at various points during the login attempt.

App Layering 2309

This release contains the following new features:

  • Option to keep the MCS deployment machine up and running. If you want to customize your deployed images from the ELM when the booted machine is being prepared for deployment to MCS, you must update your machine tools in the OS revision to revision 2309 or beyond. For more information, see Create Platform Layer.

  • Support for VHDX format for user layers. User layers are now created using the VHDX format instead of the VHD format, as in the previous releases. You do not need to convert existing user layers with the VHD format to VHDX. However, if you want to convert the user layers manually, the VHDX format of the layer is used if they both still happen to be in the same folder. If you want to create new user layers using VHD format, you can turn off the feature. For more information, see Enable User layer.

  • OS layer switching option for elastic layers is now enabled by default in the App Layering UI. You no longer have to manually enable the new OS layer switching option. For more information, see OS layer switching for elastic layers.

  • New image template option - Defragment disk when publishing the image template. You can now use the new image template option which optimizes the published image created from the App Layering appliance. This option is only available when you select an Offload Compositing connector. For more information, see Create an image template from scratch.

  • New and improved Citrix Hypervisor. When you create and manage the Citrix Hypervisor connector in App Layering, you can now experience the new UI with the modernized Hypervisor support. For more information, see Citrix Hypervisor. This release also introduces Offload Compositing support for layers and image templates in the Citrix Hypervisor. Modern virtualization technologies such as UEFI, vTPM, and Secure Boot are now available with Offload Compositing. For more information, see About Offload Compositing.


  • There is a memory leak on images that have elastic layering enabled and Sentinel One installed. [ALHELP-1708]

  • Publishing images with many layers can fail due to database size constraints.

  • The LSASS process is hung on some files and causes the boot process to fail. [ALHELP-1710]

  • VMware vSphere fails with invalid object types.

  • Purge Failure Mode waits are causing performance problems. [UNI-89518]

  • Session hosts are getting locked on the first login. [ALHELP-1722]

  • AppV packages, when preinstalled in an application layer, might either fail to launch or launch but fail to operate correctly. [ALHELP-1717]

App Layering 2306

This release contains the following new features:

  • Role-based access control is now available in the new App Layering UI. You can now assign roles to App Layering users, defining which features they can access. Any user assigned a role can log in to the management console. For more information, see Assign roles.

  • Removed support for Windows 7 and 32 bit from the ELM. All Windows 7 bit and 32-bit OS layers have been discontinued and unsupported for several versions of the ELM. If you are still using a Windows 7 bit or 32 bit unsupported OS, do not upgrade to this new version without first backing up your ELM and then contacting Support for options.

  • New App Layering tool - ScanWritableFiles. ScanWritableFiles is an application where users can identify files and folders that exist only on the writable layer (such as the User-Layer). These file-system objects are therefore not located on any other layer/volume, such as the base image or any elastically assigned layer. Identifying file-system objects of this type can be helpful when:

    • Determining what objects can be safely deleted without affecting elastically-assigned applications
    • Identifying application components directly installed by the user, versus being provided by the image or any elastic layer
    • Identifying application components installed on a packaging machine

    For more details, see C:\Program Files\Unidesk\Tools\ScanWritableFiles\ReadMe.txt.

  • New App Layering tool - AppRuleCompare. AppRuleCompare analyzes potential file system and registry conflicts between App layers, including the Platform layer if present. When run directly on an app-layered machine, AppRuleCompare “processes” the AppRule files associated with layers built into the base image, as well as those that have been elastically attached to the machine. For more details, see C:\Program Files\Unidesk\Tools\AppRuleCompare\ReadMe.txt.


  • On some Provisioning servers, the command to mount a file share with an App Layering agent greater than 2003 hangs indefinitely. [ALHELP-1593]

  • When a file or directory is created or renamed, CFS also changes the short-name of the object, which causes unexpected directory notifications. [ALHELP-1682]

  • An error in the generatePerfGenRecompileScript routine is causing the BIC to fail. [UNI-89255]

  • The rename operation is failing due to a bug in our rename logic. [UNI-89256]

  • A driver digital signature error is occurring on 2012R2 after switching to a new Citrix certification. [UNI-89258]

  • The new vSphere connecter UI is not listing all hosts. [UNI-89314]

  • A newly attached virtual disk is not being detected by VDS. [ALHELP-1694]

App Layering 2304

This release contains the following new features:

  • Registration credential support for Azure Deployments. You can now use registration credentials to configure the Azure Deployments connector, similar to what was available for the Legacy Azure connector. For more information, see Azure Deployments.

  • You can now define directory paths that are not redirected to the user layer with the user exclusions policy in Citrix Studio. Some things to note:

    • User exclusions do not override AlwaysOnBoot.
    • User exclusions apply to the full user layer and the user personalization layer (UPL), but not to the session host. The session host ignores user exclusions and adds the message to the user layer.
    • Logoff.txt now contains all active user exclusions.
  • Custom Active Directory (AD) attributes support. You can now use custom AD attributes in a user layer path for user layers and user personalization layers (UPL). AD attributes must be enclosed in hashes (for example, #sAMAccountName#). For more information, see Deploy user layers and User personalization layer.

  • New UI for the VMware vSphere connector. The VMware vSphere connector now has a new UI. For more information, see VMware vSphere.

  • Performance counters now work from any layer, including app layers and full user layers. The gold image tools must be updated in the OS revision to ensure that the performance counters are correctly rebuilt when booting an image. The OS revision needs at least one rebuild of the performance counters. Open an administrator command window in the same OS revision where you’re updating the gold image and run the commands c:\windows\system32\lodctr /r and c:\windows\syswow64\lodctr \r.

  • MSMQ can now be used from any layer included in the image. The gold image tools must be updated in the OS revision to ensure that MSMQ is properly reset and started, when present. A new log file named GenRandomQMID.log is present to indicate the actions of C:\Windows\setup\scripts\kmsdir\GenRandomQMID.ps1. This allows MSMQ to start up properly regardless of where it was installed.


  • Missing Profile key causes a failed mounting of the user layer. [UNI-88890]

  • Directory-notification code causing CPU usage spikes when disconnecting an elastic layer from a running machine. [ALHELP-1614]

  • The tool set the key HKLM\System\WPA from Never Virtualize to Virtualize Always, causing the Windows activation key to be lost. [ALHELP-1673]

  • FSLogix running with a full user layer failed login on the third and subsequent logins, causing duplicate profiles and other issues. [ALHELP-1672]

  • Deleting and recreating volatile keys causes the query handlers to block the caller from seeing the image. [ALHELP-1648]

  • SessionHost file probes missing some files, causing conflicts and leading to non-working layers. [ALHELP-1653]

  • Improved the performance of reverse-direction enumeration times. [ALHELP-1642]

  • The performance counter scanning logic opens files in Read/Share Only Read mode and cannot be turned off, causing some conflicts with files that must be continually updated by the user environment. The performance counter scanning logic now opens files in Read/Share Deny None mode and can be turned off if needed. [ALHELP-1679]

  • FSLogix search roaming sometimes does not work correctly on Elastic Layer-only images because of a new function, which is called before user login time before the layer hives are virtualized. [ALHELP-1669]

  • The Microsoft MSMQ feature is not working when finalizing the image. [ALHELP-1641]

App Layering 2211

This release contains the following new features:

  • New Azure Deployments connectors. Two new Azure connectors have been created and implemented into App Layering: Azure Deployments and Machine Creation for Azure Deployments. Both connectors also support Government environments (Azure Government and Machine Creation for Azure Government, respectively). The old Azure connector and Machine Creation for Azure connector (as well as their Government counterparts) are now deprecated, but still available for use for a limited time. For more information, see Azure deployments.

  • Block platform layer finalize if WEM RSA key detected. If the WEM RSA key exists on the platform layer, issues are caused with Workspace Environment Management (WEM). If the RSA key is detected, you now receive a message before finalizing the platform layer to remove the key. See Create platform layer for details.

  • Miss-cache mechanism improved. The default value for entries in the miss-cache mechanism has been increased from 256 entries to 1024 entries. If you have increased the default size using a registry setting, you must remove your custom setting for this enhancement to work correctly.

  • OEM drivers persist in the user layer. OEM drivers (such as printer drivers) can now be stored in the user layer and don’t require re-installation after every user logon. Possible naming conflicts among OEM drivers between the OS image and user layer are resolved automatically. After upgrading, existing user layers are scanned for any unexpected OEM traces.

  • Windows 10 and 11 22H2 support. You can now use Windows 10 and 11 22H2 as an operating system for layered images. For more information, see System Requirements.


  • Fixed an issue caused by adding the GAC_MSIL file to the registry AOB list. The GAC_MSIL file was removed. [ALHELP-1612]

  • A new ulayer setting (HKLM\Software\Unidesk\ULayer\BasicAADScrubEnabled [dword]) was added which allows you to disable Azure’s removal of Windows 10 registry and file locations. By default, this setting is set to true. [UNI-87854]

  • Fixed an issue where Purge Mode delays included files opened for read-only access, which caused the system to run slowly. [ALHELP-1621]

  • Fixed an issue where the keys in C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys were being removed when finalizing. The BIC now includes this folder. [ALHELP-1623]

  • Fixed an issue where some local policies were being removed after an OS Machine Tools upgrade. The gposetup.cmd was doing additional initialization and overwriting the gpt.ini file with the defaultgpt.ini file. [ALHELP-1627]

  • Fixed an issue causing Access Control Lists to be ordered incorrectly in newly created folders. The issue caused some entries in these folders to be ineffective. [ALHELP-1632]

App Layering 2208

This release contains the following new features:

  • Wildcard characters are now allowed to exclude a directory from a composited layer. Only one directory can be wildcarded and only one * might be used in a single path. See Exclude files from layers for more details.


  • Selecting layers for export no longer fails to save after upgrading to 2206. [ALHELP-1605]

  • Fixed issues with certain apps that occurred after upgrading to 2206. The C:\Windows\Microsoft.NET\assembly\GAC_MSIL directory is no longer excluded from app layers, and the c:\windows\system32\wbem\repository directory is only allowed on the platform layer. [UNI-87356]

App Layering 2206

This release contains the following new features:

  • Microsoft Silverlight removed. App Layering no longer requires or supports MS Silverlight. See System requirements for details.

  • A few menu items have been moved from the User tab to the System tab in the new UI:

    • Managing role access for Active Directory users and groups
    • Creating, deleting, and editing directory junctions in the Directory Service
  • More management features have been converted to the new user interface. The following features are now available in the new interface:

    • Importing and exporting layers
    • System - User Layer storage locations
  • Fully implemented new user interface! With the completion of the above, the new UI is fully implemented, and all documentation now reflects this. Many procedures and sections throughout the documentation have been updated with the new blade workflows, replacing the wizard dialogs from the old UI.

  • Custom firewall settings on user layer. Administrators can now create a script to automatically run at logon in a user layer to set up firewall options and rules for a user. The script is PrivilegedLogon.cmd and can be found at C:\Program Files\Unidesk\Uniservice\UserScripts.


  • NVivo no longer crashes when elastically assigned with Full User Layer enabled. [ALHELP-1564]

  • Folders can now be deleted in a published image after upgrading. [ALHELP-1582]

App Layering 2204

This release contains the following new features:

  • Support for Microsoft Office 2021. Office 2021 can now be used with Citrix App Layering.

  • More management features have been converted to the new user interface. You can access the new interface by way of a unique URL in your web browser. Using the IP address for the appliance, enter the following URL: https://<ip_address_of_new_vm>. The following features are now available in the new interface:

    • System Tab - Manage Appliance
    • System Tab - Settings and Configuration


  • Setting attributes of a directory no longer fails when located on a read-only volume (elastic app layer). (ALHELP-1500)

App Layering 2202

This release contains the following new features:

  • You can now force the deletion of master key files for app layers. If you get an Elastic Fit warning for an app layer due to master key file changes, you can force the deletion of master key files by editing the registry setting DeleteMasterKeys. See Deploy App layers as elastic layers for details.

  • The VMware Horizon View connector has been deprecated. If you enable or use this connector, be aware that it has been deprecated and will be removed in a future release.

  • More management features have been converted to the new user interface. You can access the new interface by way of a unique URL in your web browser. Using the IP address for the appliance, enter the following URL: https://<ip_address_of_new_vm>.

    • The following features are now available in the new interface:
      • System Tab - Connectors
      • System Tab - Settings and Configuration
      • User Menu - Upgrade appliance


  • The default setting of the ‘ManageOpenForBackup’ flag has been changed from false to true as a workaround for ACLs being corrupted on C:\windows\syswow64 and C:\windows\system32 when installing an application. (ALHELP-1327)

  • Search locations that are removed using the Indexing Options applet are now removed correctly. (ALHELP-1493)

  • Setting the attributes of a directory no longer fails when located on a read-only volume (elastic app layer). (ALHELP-1500)

  • Connections from VDAs in the process user layer are now evenly distributed across domain controllers. (ALHELP-1535)

  • The user personalization layer now installs correctly in XenDesktop. (ALHELP-1545)

  • Upgrading the Enterprise Layer Manager (ELM) from 21.06 to 21.12 no longer fails. (ALHELP-1559)

  • The user’s session now times out appropriately in the new UI. (UNI-85868)

App Layering 2112

This release introduces a new App Layering management experience and support for additional versions of Windows.

  • Support for additional versions of Windows: You can use the following versions of Windows as an OS Layer in App Layering 2112 and later.
    • Windows Server 2022
    • Windows 10 version 21H2
    • Windows 11, with the following caveat


    To support Windows 11 as an OS Layer, you must upgrade the App Layering appliance to version 2112. That version provides you with the requisite updates to the Optimizer Script builder, the Unattend Script builder, the SetKMS, and the guest installer to set the OS type. The gold image tools used to set up the gold image must be at version 2112 or later.

  • New App Layering management experience. This version of App Layering introduces Phase 1 of a new, enhanced management experience. Phase 1 of the new user interface will temporarily coexist alongside the existing user interface on the App Layering appliance. You can access each by way of a unique, distinct URL in your web browser. Note that we have not yet ported some administrative activities outside of image templates and layers to the new user interface. For those, you need to continue to use the original interface. When accessing the appliance from a modern web browser such as Chrome, Edge, or Firefox, the new management console appears. If you use Internet Explorer to access the appliance, the legacy management console appears.
    • Using the IP address for the appliance, enter the following URL in a compatible web browser:

      https://<ip_address_of new_vm>

    • Features available in the new user interface:
      • Template management
      • App, Platform, OS Layer management
      • Task management
      • Login
      • Elastic Layer user assignment
    • Browser support:
      • Microsoft Edge
      • Google Chrome
      • Mozilla Firefox


  • Office 365: Excel can become unresponsive on images created in version 2110 of the App Layering appliance. (ALHELP-1537)

  • When using Zscaler, a driver error is reported when any elastic layer is attached to the VM. (ALHELP-1528)

  • Office 365: User layers are not being attached to the session host. The issue occurs due to a file lock on PEUPTemplate.hive (ALHELP-1525)

  • App Layering 2107: VDAs can experience a fatal exception, displaying a blue screen at random. (ALHELP-1436)

App Layering 2110

This release supports:

  • VMware Cloud on:
    • Azure
    • Amazon Web Services (AWS)
  • The Citrix Provisioning connector now lets you specify a hypervisor connector configuration to use for Offload Compositing. Selecting Offload Compositing in a Citrix Provisioning connector configuration enables support for VHDX disk format, UEFI firmware, and Secure boot.

  • If Offload Compositing is enabled in a Citrix Provisioning connector configuration, you can add a custom description to the vDisk in the Publish Image wizard. For example, if you publish an image template using a Citrix Provisioning connector that has Offload Compositing enabled, you can add a comment in the Publish Layered Image wizard and the comment appears as the resulting vDisk’s description. If Offload Compositing is not enabled or you leave the Comment field blank, the description defaults to “Layered Image”. The maximum length for a vDisk description is 250 characters. If longer, it is truncated.

  • (Advanced feature) You can now exclude specific files and folders from a composited layer to prevent files from persisting on a user’s desktop. For example, you can exclude antivirus software files and folders that must not persist for a desktop from one login to the next.


  • An issue where images that include a NetApp layer become stuck at 100% CPU utilization has been fixed in cooperation with NetApp developers. (ALHELP-1508)

  • When User layers are enabled and Windows is updated, the Windows Start Menu and Search features work properly. (ALHELP-1482)

  • When you create an OS layer and a platform layer and install the Citrix Virtual Delivery Agent (VDA), the published image no longer results in a blue screen. (ALHELP-1485, ALHELP-1486)

  • The issue with MediTech Expanse after upgrading the App Layering appliance has been fixed. (ALHELP-1494)

  • The issue that prevented the successful setup and use of Dropbox on a user layer has been fixed. (ALHELP-1416)

  • The issue where the Windows search index was corrupted when creating an OS layer or adding a version to it is fixed. (ALHELP-1433, ALHELP-1453)

Labs feature

Labs features are previews of potential functionality. While a feature is in Labs, do not use it in production. There is no guarantee that this feature will be included in the product, nor that it works the same way if it is.

  • You can assign app layers as elastic layers on images that use a different OS layer: Elastic layer assignments normally require the App layer assigned uses the same OS layer that was used to create the App layer. You can try assigning an App layer as an Elastic layer on a layered image that uses a different OS layer.


    Issues can result from running an elastic layer on a different OS layer than the one used to create it.

To use a Labs feature, enable it in System settings.

Upgrade path

For the latest fixes and features, including compatibility with other software packages that you use, we encourage you to stay current with the App Layering upgrades.

You can upgrade from any App Layering release from 19.x to present.

App Layering 2107

This release includes the following improvements.


  • After upgrading from vSphere 6.7 to vSphere 7.0 Update 2 or later, you can now create layers and publish images with VSAN storage. (ALHELP-1410)

  • After upgrading to Windows 10 1909 or 20H2, ClickOnce apps now work with existing user layer disks. (ALHELP-1425)

  • An app layer that is assigned to a subset of users on a machine and contains certain Windows system files unique to the app no longer causes problems for users that are not assigned to the layer. (ALHEALP-1427)

  • On an image with EL running, you can select the remote admin share where OneDrive saves files without the machine failing with a blue screen. (ALHELP-1431)

  • When Elastic Layering is enabled on an image, a script that installs an application on the image now completes as expected. (ALHELP-1432)

App Layering 2106

This release includes the following new feature:

  • An updated version of the OS Machine Tools. We recommend that you update your OS layers with the new tools now, so that you can use any new features that require them in the future.


  • After you finalize a platform layer, the machine no longer fails with a blue screen. (ALHELP-1177)

  • When Offload compositing is enabled and you set the default size of the elastic layering volume, the writable partition size is updated for all published images. (UNI-76795)

  • When logging in after adding elastic layers to an image, users no longer receive errors like the following (ALHELP-1445):

    “Critical Error: Your Start menu isn’t working. We’ll try to fix it the next time you sign in.”

    “Citrix App Layering - System Error: An unexpected system error occurred. Retry the operation or contact technical support.”

  • Files on an elastic layer no longer disappear and reappear under certain conditions. (ALHELP-1405)

  • When using FSLogix and OneDrive with elastic layers enabled, the VM can now access the user profile folder through the admin share (\\PCName\C$\Users). (ALHELP-1386, ALHELP-1405, ALHELP-1431)

  • FSLogix Profiles now work correctly when the app is installed on an app layer. (UNI-83092)

App Layering 2104

This release includes the following improvements.


  • Synchronization of Layer version repair data now runs faster. (UNI-82197, ALHELP-1385)

  • The OfficeNoReReg.cmd script now updates existing values. (UNI-82088)

  • When accessing a published image running Windows 10 1909, you no longer receive the message, “The User Profile Service failed the sign-in. User profile cannot be loaded”. (ALHELP-1307)

  • After you install Crowdstrike, Edge launches on the first attempt. (ALHELP-1404)

  • When an image is running both elastic layering and Crowdstrike, Chrome and Microsoft Teams now launch on the first attempt. (ALHELP-1392)

  • If you install apps that have files with boot-level components and Crowdstrike tags them, the apps no longer fail after you add a version to the layer. (ALHELP-1397)

App Layering 2102

This release includes support for the following enhancements:

  • App Layering now runs on Google Cloud! You can:
    • Install an App Layering appliance on Google Cloud.
    • Create connector configurations for Google Cloud and Machine creation for Google Cloud.
    • Create layers on Google Cloud.
    • Move layers from a different platform to Google Cloud, using the Export and Import feature.
    • Publish layered images on Google Cloud, or to Machine creation running on Google Cloud.


  • Apps published from an image template with elastic layering enabled now launch as expected. (ALHELP-1306, ALHELP-1315, UNI-81247)

  • When booting a session host with UEFI and Citrix Provisioning, the session no longer fails with a blue screen on the target device. (UNI-80889)

  • Compositing no longer fails because the CE runs out of available drive letters (ALHELP-1286, UNI-80179)

  • When an app is installed on a packaging machine, MSIEXEC.EXE no longer removes permissions on syswow64 content. (ALHELP-1327, UNI-81548)

  • WebEx no longer fails with Error 1407 when trying to uninstall it from a user layer. (ALHELP-1339, UNI-81434)

  • Apps in the Windows Start menu are listed in the correct section rather than in a section with name ms-resource:AppName when user layers are enabled. (ALHELP-1323, UNI-81402)

  • Logging into the App Layering management console no longer results in a system error. (ALHELP-1332, UNI-81391)

  • VDAs no longer fail with a bluescreen on App Layering 20.11. (ALHELP-1337, UNI-82008)

  • The VDA is no longer unresponsive when users log in on to the VDA with elastic Layering enabled. (ALHELP-1369, UNI-81777)

  • Machine creation for vSphere connector no longer deletes files under UnideskCacheddisks on VMware. (ALHELP-1345, UNI-81662)

  • When assigned a user layer, you no longer get an error when accessing the Policy tab in Studio. (ALHELP-1355, UNI-81749)

App Layering 2011

This release includes support for the following enhancements:

  • We now support Nutanix version 5.18.

  • You can use Windows 10, version 20H2 as an OS Layer in App Layering version 2011 and later. However, the following caveat applies.


    If you upgrade the OS layer to Windows 10 20H2 from an earlier release, upgrade directly to Build 19042.630, or above. Upgrading to builds of Windows 10 20H2 released before 11/16/2020 can result in inconsistent image deployments. For example, if you publish images using a template with Generalize Offline selected, the published images might not work correctly.


  • Windows 10, 2004 login times. An issue where Windows 10 2004 sometimes took 2–4 minutes to start, and occasionally included black-screens for 30-45 seconds has been fixed. (UNI-80656)
  • kmssetup script not added to the startup scripts folder. An issue that prevented the kmssetup.cmd script from being added to the startup scripts folder when unzipped has been fixed. (ALHELP-1279, UNI-80410)
  • HP UPD driver not available as a printer driver. When you include an HP UPD driver in an app layer that becomes part of a published image, the driver is now available as a printer driver. The issue that prevented the driver from being listed has been fixed. (ALHELP-1278, UNI-80426)
  • Sessions hangs for minutes. An issue that caused sessions to hang for minutes has been fixed. This issue appeared after upgrading to App Layering 2005. (ALHELP-1263, UNI-80262)
  • User cannot reconnect to their desktop in App Layering 2009. An issue that caused random occasional blue screens when users tried to reconnect to their desktops has been fixed. (ALHELP-1317, UNI-81156)
  • When using the console on a 4K display, dialogue boxes open in top left corner. The issue that caused dialogue boxes to be displayed off center has been fixed. (ALHELP-1309,UNI-78951, UNI-78952)

App Layering 2009

This release includes support for the following enhancements:

  • You can now override the default repository path and layer size for user layers by configuring Citrix Studio Policies.
  • The user interface for the App Layering management console has been updated with new Citrix branding images.

App Layering 2008

This release includes support for the following features and enhancements:

  • Windows 10, 2004 support: Windows 10, 2004 is now supported as the OS for layered images. Using Windows 10, 2004 requires App Layering version 2008 or later. The required changes for this version of Windows 10 are not in previous App Layering releases.

  • Citrix Hypervisor 8.2 support We now support Citrix Hypervisor version 8.2.


App Layering 20.8.3 includes an important update to the included drivers. If you are using a secure boot, you must upgrade to 20.8.3!

The 20.8.3 installation and upgrade packages are available for download. For new installations, download the Appliance Installation Package. For upgrades, download the Appliance Upgrade Package.


  • VM in vSphere with elastic layers enabled no longer fails after being deployed to a Citrix Provisioning server. An issue that had caused a VM in vSphere with elastic layers enabled to fail after being deployed to a Citrix Provisioning server was fixed. (ALHELP-1202, UNI-76300)
  • An issue that had caused the AutoDesk 2020 installer to fail in an app layer has been fixed. (ALHELP-476)
  • Users can now synchronize their OneDrive files without issues when On Demand syncing and Elastic layers are enabled (ALHELP-468)
  • Chrome extensions no longer cause the error message, “FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY,” when elastic layers are enabled and an app layer is assigned. (ALHELP-419)

App Layering 2005

The App Layering 2005 release includes support for the following features and enhancements:

  • Security enhancements: Security enhancements include cipher suite updates, third-party component upgrades, and runtime environment upgrades.

  • Secure boot support: Guest drivers are certified via Microsoft’s WHQL program. You can use certified guest drivers in secure boot configurations. (UNI-74917)

  • Customer user layer path: User layer files can now be stored in network shares whose locations are specified using custom paths. The custom paths can include environment variables. (UNI-78291)

  • Applications with services in user layer: When an application installed in a user layer contains Windows services, such as Google Chrome, those services are started as expected when the user logs in. (UNI-77660)

  • 2005 upgrade package: The App Layering 2005 upgrade package is large enough that older appliances cannot download it automatically. If you are running version 1911 or older, download the package manually from the downloads site. Also, we recommend running the upgrade from a management console in Secure HTTP (HTTPS). If you upgrade while in HTTP, messages do not display in the browser. If that happens, refresh the browser after 20 minutes. (Refreshing won’t cause issues in spite of the message that says not to refresh.) If the upgrade is still running, you get a “service unavailable error.” You can ignore that message and keep refreshing the browser every few minutes until the login page appears.


  • When using offload compositing with VMware vSphere, you can use layer names that start with brackets [], as long as you follow the closing bracket with a space. For example, the name [OS] Windows 10 works, but the name [OS]Windows 10 hangs in vSphere studio and times out after about 40 minutes. (UNI-78452)

App Layering 2003

This release includes the following:

  • We now support the following hypervisor, provisioning, and connection broker software versions:

    • Citrix Hypervisor 8.1
    • Nutanix AOS 5.16
  • When administrators configure a larger default user layer size, the disk will be automatically expanded the next time the user logs in.

  • When creating your OS layer in MS Hyper-V or VMware vSphere, you can now import the OS image, by using a script in the OS Machine Tools. The script imports the OS image right from the virtual machine, instead of using the management console and connector configuration. The script uses the Offload Compositing feature, which speeds up the import, and allows you to use a wider variety of virtual machines, including UEFI-based machines.


  • The Guest Layering service (ULayer) has been modified to not depend upon the Server service running on the end users’ virtual machines. (UNI-77242)
  • When delivered as an elastic layer, the Artiva application no longer fails when users attempt to log in. (UNI-76487)
  • An issue that had caused the StartCCMEXEC.cmd script to continually grow the log file, StartCCMExec.txt, even when CCMExec was not installed, has been fixed. To apply the fix, download the new OS Machine Tools folder for 20.3, and replace the StartCCMEXEC.cmd file with the new version. (UNI-77471)
  • When users install fonts on a user layer or elastic layer, the fonts persist the next time they log in. (UNI-63839)
  • When using a connector with Offload compositing enabled to publish an image, 8.3 file names are no longer incorrectly modified. (UNI-76961)
  • When adding a version to an app layer, you no longer receive the error “The Operation Failed due to a missing File. VMDK was not found.” (UNI-77702)
  • The issue with expiring JSON Web Tokens (JWT) when using the Offload Compositing feature in the connector configuration has been fixed. (UNI-76859)
  • The Hyper-V connector now reports the disk file size rather than its logical size, which was quickly filling up the cache. (UNI-76692)
  • Compatibility with Citrix Studio GPO policies when using images with user layers has been improved. (UNI-76918)

App Layering 2001

This release includes the following:

  • We now support the following hypervisor, provisioning, and connection broker software versions:
    • Citrix Provisioning version 1912
    • Citrix Virtual Apps and Desktops version 7 1912
  • The following Windows 10 versions are now supported as an OS Layer:
    • Windows 10, version 1909
    • Windows 10, Enterprise Virtual Desktop edition (available from Microsoft in Azure only)
  • Our VMware vSphere connector now supports the VMware Paravirtual SCSI Controller. (UNI-75620)


  • In our App Layering appliance (ELM) deployment script for Azure, we have extended the expiration dates of signed Azure URLs pointing to standard repository disks. Make sure that you update your Azure deployment scripts from this release accordingly.
  • VDA installations no longer fail on a packaging machine. (UNI-76299)
  • When restarted, a layered image with a user layer no longer drops scheduler tasks. (UNI-77084)

App Layering 1911

This release includes the following:

  • We now support the following hypervisor, provisioning, and connection broker software versions:
    • XenApp and XenDesktop 7.15 LTSR CU5
  • VMware vSphere:
    • Use the new Offload compositing option to significantly reduce the time it takes to package layers and publish images.
    • Select thin provisioned disks and UEFI (no secure boot with elastic layers and user layers) options.
    • Use the vSphere connector to package layers and publish images to VMware Cloud on AWS.


  • An error when finalizing OS layers with MBR partitions after a major Windows 10 upgrade has been fixed. (UNI-76210)
  • Compatibility with the Microsoft System Center Configuration Manager (SCCM) has been improved. (UNI-76198, UNI-76126, UNI-76129)
  • Users no longer lose their connection to a session host where FSLogix is running and elastic layering is enabled. (UNI-73793)
  • Rapid Reader 8.3 now starts as expected after being installed on a packaging machine. (UNI-76316)
  • IntelliJ IDEA Ultimate no longer freezes the desktop when the app is started. (UNI-76075)
  • Users no longer get a blue screen when they open SQL Management Studio and attempt to save a Query to OneDrive or a SharePoint folder. (UNI-76427)

App Layering 1910

This release includes the following:

  • We support the following new versions of hypervisor, provisioning, and connection broker software:
    • Citrix Virtual Apps and Desktops version 7 1909
    • Citrix Provisioning version 1909
    • Nutanix Acropolis Hypervisor (AHV) version 5.11
    • VMware Horizon View 7.9
  • On the Hyper-V platform, you can package layers and publish images using Offload Compositing to dramatically improve performance and compatibility. Gen2 VMs and VHDX disk formats are now supported.

  • The App Layering Agent has been updated to support the new Offload Compositing feature. If you use the agent in your deployment, we strongly recommend that you install the agent update on any servers where it is installed.

  • Windows Search index performance is improved when using full User Layers.

  • For administrators publishing layered images, this version adds validation and warnings to give guidance on what disk size to use based on selected app layers.


  • A PVS Support article that called for removal of the CDF Driver Registry entry has been updated to fix issues troubleshooting Profile Management. (UNI-75720)
  • The issue where Defender didn’t update correctly has been fixed. (UNI-74918)
  • Windows Search Service starts as expected on a packaging machine when using a caching connector. (UNI-75915)
  • Windows Defender now starts successfully on an app layer created from a Windows 1809 OS layer. (UNI-74997)
  • Users can now sync their OneDrive files when On Demand syncing and elastic layers are enabled. (UNI-74618)
  • OneDrive’s on-demand feature now streams files correctly when elastic layering is enabled. (UNI-73121)
  • User layer repairs now complete successfully when the minimum recommended permissions are set on the Users\ path. (UNI-75552)
  • When installing a Chrome extension with user layers enabled and an app layer assigned as an elastic layer, you no longer receive the error Can not install package: FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY (UNI-75568)
  • Windows Search index performance has been improved when using full user layers. (UNI-73049)
  • This release adds validation and warnings about what disk size that you can use. The guidance is based on your configuration and the app layers selected. (UNI-54390)

App Layering 1908

This release includes support for these new features and improvements.

  • Windows versions: Windows 10 version 1903 is now supported as an OS Layer.

  • Connection brokers: We now support the following connection broker software version:
    • VMware Horizon View 7.9
  • User layer repair: You can now manually repair user layers so that all files and registry settings coming from a specific set of app layers can be made visible again.


  • Hyper-V connector PowerShell sessions no longer expire when a file copy takes longer than 30 minutes. (UNI-74283, UNI-74292)

  • The issue where System and Display properties did not open correctly when user layers were enabled has been fixed. (UNI-74547)

  • Removing store apps from a Windows 10 OS layer no longer causes features, like Settings and Display Properties, to malfunction. (UNI-74852)

  • The Windows Defender update KB4052623, now successfully installs and works for user layer-enabled users. (UNI-74942)

Contact Citrix

We welcome your feedback about this release.

  • Use our online Forum to speak directly with Citrix employees and other organizations deploying Citrix App Layering.
  • For product issues and questions, open a Support Case.

We look forward to hearing what you think about App Layering.