Firmware Update


  • With activated DRI3 and an AMD GPU Citrix H.264 acceleration plugin could freeze. Selective H.264 mode (API v2) is not affected from this issue.
  • Citrix has known issues with GStreamer1.0 which describe problems with multimedia redirection of H.264, MPEG1 and MPEG2. GStreamer1.0 is used if browser content redirection is active.
  • Browser content redirection does not work with activated DRI3 and hardware accelerated H.264 deep compression codec.
  • Citrix H.264 acceleration plugin does not work with enabled server policy Optimize for 3D graphics workload in combination with server policy Use video codec compression > For the entire screen.
  • To launch multiple desktop sessions with Citrix HDX RTME and Citrix H.264 acceleration plugin, the following registry key must be enabled. 

    ParameterActivate workaround for dual RTME sessions and H264 acceleration
    Valueenabled / disabled

    This workaround is not applicable when "Enable Secure ICA" is active for the specific delivery group.

  • Adding smartcard readers while the session is ongoing does not work. The reader is visible, but cannot be used due to permanently unknown reader status.

VMware Horizon

  • Client drive mapping and USB redirection for storage devices should not be enabled both at the same time.
    • On the one hand, when using USB redirection for storage devices: The USB on-insertion feature is only working when the client drive mapping is switched off. In the IGEL Setup client drive mapping can be found in: Sessions > Horizon Client > Horizon Client Global > Drive Mapping > Enable Drive Mapping. It is also recommended to disable local Storage Hotplug on setup page Devices > Storage Devices > Storage Hotplug.
    • On the other hand, when using drive mapping instead, it is recommended to either switch off USB redirection entirely or at least deny storage devices by adding a filter to the USB class rules. Furthermore, Horizon Client relies on the OS to mount the storage devices itself. Enable local Storage Hotplug on Setup page Devices > Storage Devices > Storage Hotplug.
  • External drives mounted already before connection do not appear in the remote desktop. Workaround: map the directory /media as a drive. Then the external devices will show up inside the media drive.
  • After the disconnect of an RDP-based session, the Horizon main window which contains the server or sessions overview cannot be resized anymore.
  • Copying a text from Horizon Blast sessions is not possible.
  • The on-screen keyboard in Horizon appliance mode does not work correctly with local logon.
    Workaround: Switch off local logon and switch on the corresponding two keys via IGEL registry:
    • userinterface.softkeyboard.autoshow
    • userinterface.softkeyboard.autohide
  • Zoom VDI Media Plugin makes Horizon Client crash upon connection to the remote desktop in cases when TC Setup is running at the same time.


  • H.264 decoding is not supported anymore.


  • TP-Link Archer T2UH Wi-Fi adapters do not work after system suspend/resume. Workaround: Disable system suspend at IGEL Setup > System > Power Options > Shutdown.

Parallels Client

  • Native USB redirection does not work with Parallels Client.

Cisco JVDI Client

  • There may be a segfault shown in the logs (during logout of Citrix Desktop session). This occurs only when using Citrix Workspace app 20.10 and Cisco JVDI.


  • Multimedia redirection with GStreamer could fail with the Nouveau GPU driver.


  • Hyper-V (Generation 2) needs a lot of memory (RAM). The machine needs a sufficient amount of memory allocated.


  • The current VirtualBox Guest Tools/Drivers will not work with VirtualBox 5.2.x or older hosts which leads to a black screen and non-working graphics.
    Possible workaround: Install with 'Failsafe Installation + Recovery' and set the registry key x.drivers.force_vesa to 'true'.


  • Audio jack detection on Advantech POC-W243L doesn't work. Therefore, sound output goes through a possibly connected headset and the internal speakers.
  • IGEL UD2 (D220) fails to restore the volume level of the speaker when the device used firmware version 11.01.110 before.


  • Some newer Delock 62599 active DisplayPort-to-DVI (4k) adapters only work with INTEL devices.

Remote Management

  • AIT feature with IGEL Starter License is only supported by UMS version 6.05.100 or newer.

Base system

  • Update from memory stick requires network online state (at least when multiple update stages are involved).
  • Unreliable messages in user dialog for applying settings during boot. Could occur when new settings were fetched from the UMS.


  • Some stability issues may remain.

Appliance Mode

  • When ending a Citrix session in browser appliance mode, the browser is restarted twice instead of once.
  • Appliance mode RHEV/Spice: spice-xpi firefox plugin is no longer supported. The Console Invocation has to allow 'Native' client (auto is also possible) and should be started in fullscreen to prevent any opening windows.