With Citrix ICA policies, you can specify whether or not apps should be able to assign virtual channels to each other. In order to use Zoom Meeting on a VDI environment, you need to open a virtual channel. To provide an optimized meeting and Zoom Phone experience, Zoom uses the virtual channel to connect to the Zoom VDI Plugin on the thin client to get in touch with the Zoom VDI Plugin on the thin client.

From Citrix VDA 2109 onwards, the default virtual channel allow list policy will be “Disabled” instead of “Enabled“. You may experience this problem even if you are upgrading an existing installation in which the policy has not been changed. A virtual channel can be opened by Zoom only if additional steps are taken.

There are a number of topics covered in this article, including:

• Changing the virtual channel allow list policy to “disabled”
• How to add values for Zoom VDI client installation when the virtual channel allow list is enabled

Prerequisites for configuring the Citrix Virtual Channel Allow List policy for Zoom

There is an assumption in this article that the reader knows how to use Citrix Studio in addition to having access to and permissions to make the necessary changes.

How to change the Virtual Channel Allow List policy to disabled

Thankfully, there is a simple solution to ensure that Zoom can create and open a virtual channel for the purpose of connecting to your VDI plugin, and that you can achieve this by setting the virtual channel allow list policy to “disabled”. The policy state can be changed to “disabled” if it was changed to “enabled” after the policy was updated to release 2109, or the policy can be edited so that the status is returned to “disabled”.

In Citrix Studio, you will need to select the ICA policies section and navigate to it from there. You will need to find an appropriate location in the virtual channel allow list policy where you can update the policy and set it to “disabled”.

It is important to note that if users are able to download and install software themselves via their virtual desktops, we suggest that the virtual channel allow list is set to “disabled”. It is important to note that if you do not select the installation default for “all users” when installing, you will not be able to create a policy exception that applies to an individual user if the path for all users (provided below) is not set.

How to add values for the Zoom VDI client to the Virtual Channel Allow List

You will need to add the Zoom application to the list of applications that are allowed on those virtual channels if you wish to keep the virtual channel policy configured for “enabled”.

1. By copying each channel, exe file, below into the virtual channel allow list policy in Citrix Studio, you will be able to add the values for Zoom VDI client installation:
   • ZOOMHDX,C:\Program Files (x86)\ZoomVDI\bin\Zoom.exe,C:\Program Files (x86)\ZoomVDI\bin\ZoomVDITool.exe
   • ZOOMHDC,C:\Program Files (x86)\ZoomVDI\bin\Zoom.exe
   • ZOOMHDA,C:\Program Files (x86)\ZoomVDI\bin\Zoom.exe
   • ZOOMHDS,C:\Program Files (x86)\ZoomVDI\bin\Zoom.exe
   • ZOOMHDV,C:\Program Files (x86)\ZoomVDI\bin\Zoom.exe
   • ZOOMPHX,C:\Program Files (x86)\ZoomVDI\bin\Zoom.exe
   • ZOOMAUS,C:\Program Files (x86)\ZoomVDI\bin\Zoom.exe,C:\Program Files (x86)\ZoomVDI\bin\ZoomVDITool.exe
2. The path to the Zoom.exe file that you need to install ZoomVDI in your environment can be changed from the default path C:/Program Files (x86)/ZoomVDI/bin/ to the path where you want to install Zoom.exe.
3. The changes will take effect as soon as you restart the VDA environment.

More information can be found in the policy regarding virtual channel allow lists.