Citrix Virtual Apps and Desktops

Virtual channel allow list policy settings

This setting enables the use of an allow list that specifies which virtual channels are allowed to be opened in an ICA session.


This setting applies only to Citrix Virtual Apps and Desktops 1912 LTSR CU2 and later.

When disabled, all virtual channels are allowed.

When enabled, only Citrix virtual channels are allowed.

To use custom or third-party virtual channels, add the virtual channels to the list. To add a virtual channel to the list, enter the virtual channel name followed by a comma, and then the path to the process that accesses the virtual channel. More executable paths on the VDA can be listed, and the paths are separated by commas.

For example,


CTXCVC2,C:\VC2\vchost.exe,C:\Program Files\Third Party\vcaccess.exe

By default, virtual channel allow lists are disabled.

If you’re using the HDX RealTime Optimization Pack for Skype for Business, add the virtual channel to the allow list. For more information, see the HDX RealTime Optimization Pack documentation.


When you enable the setting, make sure that the text box does not contain the text Disabled. Otherwise, the feature remains disabled.

The VDA machines must be rebooted for the setting to take effect.

For more information about virtual channels, see ICA virtual channels.

Citrix Multimedia (CTXMM) virtual channel

When this policy is enabled, you must add CTXMM to the allow list. Otherwise, issues might occur with the multimedia redirection.

Applications that use multimedia redirection must be added to the Virtual Channel allow list.

For example: Windows Media Player uses multimedia redirection. With this policy enabled, you must add the following in the Virtual Channel allow list:

CTXMM c:\Program Files (x86)\Windows Media Player\wmplayer.exe i.e CTXMM ProcessPath

Virtual channel allow list policy settings