App Layering

What’s new in App Layering 4.5

Release date: September 7, 2017

  • You can select layers to export and import. You can now select specific layers to export or import. (UNI-57370)

  • The Elastic FIT analysis runs on newly imported layers. When new layers are imported into an appliance, an Elastic Fit analysis now evaluates how well each of the layers is likely to do if elastically assigned. (UNI-59617, UNI-59604)

  • Unidesk site resources replaced. The resources on the website have been replaced with equivalent resources on Please use these resources instead:
  • Child domains in Active Directory are now supported. App Layering now supports distinct child domains in Active Directory. You can now set multiple child domains as well as the parent domain and have them independently accessed. For example,, and itself. (UNI-60803, UNI-55158)

Issues fixed in this release

  • When you import layers, an Elastic Fit analysis is run on the layers so that the layers’ Elastic Fit status is restored, and no longer lost. (UNI-59617)

Labs features in this release

Labs features are early versions of features planned for future releases. Typically, new Labs features are disabled when you install the product. In this release, Labs features include:

User Layers. You can persist user profile settings, data, and user-installed applications in non-persistent VDI environments with the user layer. This layer supports Windows 7 64-bit and Windows 10 64-bit environments for Citrix XenDesktop, VMware Horizon View, and View JIT.

Access the management console in Citrix Cloud (Labs). You can access the App Layering management console through the Citrix Cloud App Layering Manage tab. For a new installation, see Access the Management Console and then select your hypervisor for steps and known issues. For upgrades from an App Layering 4.0.x release, see Upgrade and then select your hypervisor.

Export and import layers (App Layering Labs). You can move layers from one App Layering appliance to another by using the layer export and import feature. For example, you can move layers from your proof of concept environment to an appliance in your production environment. Starting in the 4.5 release, you can select a specific set of layers to export or import.

Supported platforms

For information about Citrix App Layering -supported platforms, see System requirements.

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.

If you have chosen to stay on a version of the App Layering product released before version 19.1, see the Upgrade article for the upgrade path and the download link for the version that you need to upgrade to first.

Known issues and considerations

Integration with other Citrix software

Access the management console through Citrix Cloud (Labs). You can access the App Layering management console through the Citrix Cloud App Layering Manage tab. For a new installation, click here for steps and known issues. Click here if you are upgrading from an App Layering 4.0.x release.

File downloads from Citrix ShareFile. You can download files by using Citrix ShareFile but you cannot save changes to the files. (UNI-55850)

Issues with Labs features

User Layer

  • A red “X” network adapter icon indicates that there’s an issue even when the network is functional. You can ignore the red ‘X.’ (UNI-53443)

Export and Import Layers

  • You must import layers onto a system that does not already include those layers. Do not attempt to re-import a layer.

User Layers on Windows 10

You can disable Windows 10 Store apps on Windows 10 Enterprise only. If you want to disable Windows 10 Store apps, do the following:

  • Create an operating system revision.
  • From an administrator command prompt, run the script at C:\Windows\Setup\Scripts\RemoveStoreApps.cmd.
  • Finalize and deploy the image based on this operating system revision.

Users have access to Edge and Cortana only. (UNI-56935)

Store tile reconstruction

After you upgrade to Windows 10 in the OS layer, store tile reconstruction can occur when users log on for the first time. The reconstruction period is less than one hour.

Reconstruction can take longer depending on system load factors and the behavior of Windows. During this period, users can notice that the Start menu tiles lack proper icons or do not respond. Usually, tile response is slow and can appear broken. However, these conditions resolve themselves during the reconstruction period. Other (non-tile) applications continue to work but can run slower because of the reconstruction activities in the background. Users initial log on following a major operating system upgrade can take longer because of reconstruction activities. It is considered normal post-upgrade behavior.

Major version of Windows 10

If you revert to an earlier major version of the Windows 10 OS layer, the user layers are not compatible. For example, reverting from version 1607 to 1511. Rolling back from one subrelease to another is fine. If the user layers are not compatible, delete and recreate the user layers. (UNI-57006)

Temporary element not found

An error message appears that the temporary element is not found. Some newer versions of Windows 10 use Store apps as default applications. Attempting to open a file with an association to one of those applications can result in an “Element not found” message. Users can wait until the application is ready to use through Windows Store. (UNI-57749)

User Layers on Windows 10 and Windows 7

Changes to Windows indexing options do not persist when you enable user layers on Windows 10 and Windows 7 desktops. If you set Indexing Options for an elastically layered app, the settings are not available when users log on. If an indexing option change is critical for all users, you can include it in a new version of the OS layer. You can also include it in a new app layer, which is a better option. The change becomes the default for all users. (UNI-56064, UNI-56213)

Issues common to all platforms

App Layering appliance and management console

  • After upgrading from App Layering 4.1.0 or 4.2.0 to the current release, you might need to reset the App Layering administrative passwords.
  • When accessing the App Layering appliance through Internet Explorer running on a server operating system, the fonts for the management console might not load correctly. To prevent this issue, add the appliance IP address to the Trusted Sites list in Internet Explorer. (UNI-50830).
  • Restart the appliance after adding new disks. When adding disks to expand storage, Citrix recommends that restarting the appliance after the disk expansion wizard completes the operation. (UNI-53580)
  • If an IP address is already in use with another virtual machine, configuring a different IP address on the appliance can cause a network service failure. For example, if the app layering appliance has a dynamic IP address and you reconfigure it to use a static IP address. An error message, “Job for network service failed.” If the appliance loses network connectivity, change to an unused IP address and restart the appliance.

OS Layer

  • Use the same hypervisor when adding a version to your OS layer. When adding a version to an OS layer, package the layer on the same hypervisor from which you imported the OS during layer creation. (UNI-44372)
  • Automatic Windows Updates are disabled during OS Layer updates. When you update the OS layer, Windows Updates are disabled automatically. Disabling automatic updates help avoid situations where Windows starts an update in the background before, or during, an OS layer finalization. When you add a version to an OS layer, manually start the download and installation of Windows updates. Then repeat the downloads and installation until you apply all available updates before finalizing the new OS layer. (UNI-58115)

App Layers

  • Use the built-in administrator account when you log on to a packaging machine. Otherwise, RunOnce scripts do not run, and finalization of the layer does not occur. (UNI-58154)
  • Apps can appear to load slowly in user sessions. Disable automatic updates for applications, such as Chrome and Firefox. Windows prompts the user to make changes with an administrator account even though the user does not have administrator access. Instruct the user to click No when prompted and then the application starts successfully.

Elastic Layering (general)

  • Users receive the following alert when starting an elastically assigned Skype layer for the first time: “The Installer has insufficient privileges to modify this file: URL “ If the user clicks Ignore, Skype opens as expected. (UNI-52164)
  • Empty directories are visible to Windows Explorer users when Citrix App Layering drivers are running. When you enable an image with elastic layering, users might be able to view files and directories from other sessions in Windows Explorer. If users browse files with Windows Explorer, they might be able to see empty directories associated with other sessions that use elastic layering. Directories explored in the other session might create folders visible to all sessions that have permission to browse that directory. If users access to the volume is not available, they cannot see the directories and contents of the drives.
  • Elastic layers require .NET Framework 4.5. If you are using Citrix App Layering elastic layers, install .NET Framework 4.5 on any layered image where you enable elastic layers.
  • If you use elastic layer assignments with Windows Server 2008 or Windows 7, create your file share with a sector size of 512. For details about this issue and related operating system updates, see the following:
  • When using Elastic Layer Assignments, Persona Management in Horizon View is not supported. Although Citrix App Layering supports Horizon View 6.1 and later, Elastic Layer Assignments do not support these versions of View Persona Management. (UNI-53639)
  • Citrix App Layering supports Horizon View 6.1 and later. Elastic layer assignments do not support Persona Management in Horizon View. (UNI-53639)

Windows 10

  • Windows 10 Creator’s Update (version 1703) is not yet supported. Citrix does not recommend using the Windows 10 1703 Creators Edition at this time.
  • Windows 10 upgrades require a 60-GB disk for the OS layer version. When you add a version to the Windows 10 OS layer, change the maximum layer size from 30 GB to 60 GB.(UNI-52422)
  • Upgrading requires extra steps when going to a new Windows 10 major release.During the upgrade, Windows 10 can create a recovery volume on the same disk as the OS layer version. Always delete this volume before you finalize the OS layer version. Otherwise, the recovery volume can cause desktops to fail to start correctly. For more information, see App Layering: Windows 10 upgrade may result in new recovery volume partition.

Citrix Provisioning Services (PVS)

  • When you create an image template, the target device hardware settings must match the Windows operating system and platform layer settings. Ensure that the hardware settings on the target device match the operating system and platform layer hardware settings, especially the number of CPUs. If the settings don’t match, you can get a restart required message when you start the published image.(UNI-50799, UNI-46333, UNI-51599)
  • If you use Provisioning Services, you must disable IPv6 in the OS layer. If you disable IPv6 in the platform layer instead of in the OS layer, when Provisioning Services start, the network connection fails and stops responding. (UNI-53600)
  • If permissions are wrong when you publish an image, an error message might appear that says the operation timed out. (UNI-54516)
  • Although the management console allows image names that contain a period (.), those names fail in the Provisioning Services environment. Do not include a period in the name. (UNI-54263) UNI-54263)

Citrix Hypervisor

  • When you prepare your operating system image for use in Citrix Hypervisor, you must open port 5900. (UNI-50846)
  • Creating a Citrix App Layering connector configuration that points to a child node in a Citrix Hypervisor pool produces an unexpected error message. To avoid this issue, only use the primary node when creating connector configurations. (UNI-52454)
  • When you import an OS layer from a Citrix Hypervisor virtual machine, use the Citrix Hypervisor connector to perform the import directly. There might be issues exporting the virtual machine image to a network file share first and then importing it to Citrix Hypervisor.(UNI-52669)

VMware Horizon View

  • Elastic layers are only supported with floating desktop pools. (UNI-53442)

Microsoft Azure

  • Citrix App Layering does not support Azure File storage. Create a network file share or an SMB file share in Azure to use with Citrix App Layering. (UNI-42272)
  • If the fully qualified domain name (FQDN) is not typed in the format Azure expects, the FQDN in Azure can fail. For more information, see Create a fully qualified domain name in the Azure portal for a Windows VM.(UNI-51587)
  • The Azure connector configuration name must be unique. When creating an Azure connector configuration, you cannot use the same name that is in an existing configuration. If you do use the same name, you cannot save the changes. (UNI-56230)

Microsoft Hyper-V

  • When you configure Elastic Layering in Hyper-V, you must use unmanaged RDS pools (UNI-53545)
What’s new in App Layering 4.5