Launching a Citrix Published Application from a Citrix Published Desktop may cause the Windows Taskbar running in the Published Desktop to stop responding. 

Caution! Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Be sure to back up the registry before you edit it.

The issue is due to the Hybrid Mode in Citrix Workspace App that leverages DirectX11 and GDI+ for rendering graphics from the 2nd hop. 

Caution! Refer to the Disclaimer at the end of this article before using the Registry Editor.

Note: this varies depending on the version of Citrix Workspace App (CWA) Installed on the Multi-session VDA:

For Citrix Workspace App 2503 and subsequent versions:

1. 1. On the VDA hosting the shared Virtual Desktop, create a new Registry Key named: GfxRender Under: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\ICA Client\Engine\Configuration\Advanced\Modules
   2. Under this GfxRender registry key create the following value:
      • Name: UseD3D11
      • type: REG_DWORD
      • Data: 0
   3. For the setting to take effect the system needs to be restarted.

For Citrix Workspace App 2409 and previous versions:

1. 1. On the VDA hosting the shared Virtual Desktop, create a new Registry Key named: GfxRender Under: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\ICA Client\Engine\Configuration\Advanced\Modules
   2. Under this GfxRender registry key create the following value:
      • Name: UseD3DHybrid
      • type: REG_DWORD
      • Data: 0
   3. For the setting to take effect the system needs to be restarted. 

This article describes a workaround for the issue where the Windows Taskbar in a Published Desktop hangs when launching a Published Application.