Omnissa Horizon Client for Linux Release Notes

Horizon Client for Linux 2111.1 | 15 MAR 2022

What's New

Horizon Client for Linux 2111.1 fixes the keyboard issue that caused repeating keystokes.

For information about new remote desktop features, see the Omnissa Horizon 8 2111 Release Notes.

Localized Content for Omnissa Docs

The transition from Broadcom to Omnissa is in progress. As part of that transition, we are reviewing our localization strategy for how best to serve the needs of our customers and partners. We will be providing localized version of Omnissa Docs content again soon. Thank you for your patience.

Note: To have the client user interface use Simplified Chinese characters, set the client system to use the zh_CN locale. If you set the client system to use the zh_SG locale, the user interface is displayed in English characters.

Before You Begin

Note: The supported systems listed below and in the Horizon Client for Linux Installation and Setup Guide pertain to the Horizon Client for Linux that Omnissa makes available. In addition, several Omnissa partners offer thin and zero client devices for Horizon deployments. The features that are available for each thin or zero client device, and the operating systems supported, are determined by the vendor and model, and the configuration that an enterprise chooses to use. For information about the vendors and models for these client devices, see the Omnissa Compatibility Guides.

• Horizon Client for Linux has been tested and is supported on the following 64-bit operating systems if you use the installer provided by Omnissa:

  • Ubuntu x64 18.04 and 20.04
  • Red Hat Enterprise Linux (RHEL) 7.9 and 8.5

• Horizon Client for Linux is supported on Raspberry Pi 4 Model B devices that are installed with ThinLinx Operating System (TLXOS) or Stratodesk NoTouch Operating System with limitations. The supported Horizon Client features include Omnissa Horizon Blast Extreme, USB redirection, Real-Time Audio-Video (RTAV), and H.264 decoding (for one monitor at resolution lower than 1920 x 1920).

• Horizon Client for Linux is supported with Omnissa Horizon 8 version 2006 and later.

• To install Horizon Client for Linux, download the installer from the Horizon Clients download page.

• Horizon Client for Linux does not ship with the GTK+ library, but it does use the library installed on the host system. Make sure your system is up to date with a version of the library that includes fixes for publicly reported security vulnerabilities. A list of the publicly reported security vulnerabilities, and the versions affected, for GTK+ can be found at https://www.cvedetails.com/vulnerability-list/vendor_id-666/GTK.html.

• For information about the features that are supported in nested mode, see Omnissa Knowledge Base (KB) article 67248, "Horizon Guidelines for Nested Mode."

• Beginning with Horizon Client for Linux 2006, Virtual Printing (also known as ThinPrint) is not supported. Use Integrated Printing instead.

For more system requirements and detailed installation instructions, see the Horizon Client for Linux Installation and Setup Guide.

Resolved Issues

When using Horizon Client 2103 and 2111, keystrokes get repeated intermittently.

Known Issues

• Application Sessions
• Printing
• Real-Time Audio-Video (RTAV)
• Miscellaneous
• Display
• Keyboard and Mouse
• RDP
• Multimedia Redirection (MMR)
• HTML5 Multimedia Redirection (HTML5 MMR)

Application Sessions

• System Tray redirection functionality is not supported

System Tray redirection functionality is not supported so you can not exit a remote application session using the system tray.

Workaround: Use the remote application's UI to end the application session. For example, to exit a Skype session, select the Settings icon and then select File > Exit.

• You cannot start an application from the Application Launcher because the launcher is unsupported.

Workaround: Start the remote application via the Linux client's UI.

• System hangs may occur when using remote applications from a client system running Stratodesk.

Workaround: Reduce the GPU memory to 128 MB. For example, in Stratodesk running on a Raspberry Pi, go to Configuration > Services > Raspberry Pi and change GPU memory (MB) to 128.

• When using Microsoft Teams Optimization Pack with Horizon Client for Mac or Horizon Client for Linux published applications, screen sharing is not supported.

Workaround: None.

Printing

• If multiple Horizon clients connect to the same published desktop or published application simultaneously and map to a location-based printer with the same name, the printer appears in the first client session, but not in later client sessions.

Workaround: For the client sessions in which the printer does not appear, perform a manual refresh. For a remote desktop, press F5 or refresh the Devices and Printers window. For a remote application, close and reopen the application print dialog box. The location-based printer appears in the printer list.

Real-Time Audio-Video (RTAV)

• When a Raspberry Pi 4 client user tries to play RTAV video at custom high resolutions (such as 1280 x 800) not supported by the connected USB webcam, the video fails to display in the remote desktop.

Workaround: Use a standard resolution that is supported by the connected USB webcam.

• When a Raspberry Pi 4 client user plays RTAV video at high resolution, the frame rate (FPS) of the video is low due to the limited CPU and memory of the client device.

Workaround: None

Miscellaneous

• Issues when client system runs pcsc-lite version 1.5.

Smart card removal policy may not work, logging off, shutting down or resetting a Windows remote desktop may result in a black screen, or the Horizon Client menu may become blank for about 10 seconds when a user has smart card sessions to multiple desktops and the user disconnects from one desktop.

Workaround: Upgrade to pcsc-lite 1.7.4 or later.

• If you use a PulseAudio sound system, you might hear static when setting the volume using guest system volume slider.

Workaround: Use the Linux client system's volume slider or use ALSA audio by adding sound.backendType = alsa to the config file nested under Home or /etc.

• When a RHEL 7 client user connects to a published Windows Server desktop using the Horizon Blast display protocol and attempts to log out from the session, Horizon Client might hang.

This issue is caused by conflicting processes associated with version 1.8.8 of the PC/SC Lite (pcsclite) library.

Workaround: On RHEL 7 systems, upgrade the pcsclite library to a version later than 1.8.8.

• Horizon Client crashes upon connecting to a remote desktop.

This known issue occurs under the following conditions:

* Horizon Client is running on an Ubuntu 20.04 system with Intel Ice Lake or later hardware, and
* Session protocol is Horizon Blast with HEVC 4:4:4 encoding

The Intel media driver that ships by default with Ubuntu 20.04 contains a bug that causes Horizon Client to crash. Later versions of the driver contain a fix for this bug.

Workaround: Update the Intel media driver by installing the latest version of intel-media-va-driver-non-free.

Display

• On some HP thin clients that have HP ThinPro 5.2.0 (T6X52011) operating system, Horizon Client for Linux might display a black screen or crash when user is playing some video on a remote desktop and pressing the fast-rewind button on Windows Media Player.

Workaround: Upgrade the OS to HP ThinPro 6.1.0 (T7X61007) or the latest version.

• The Horizon Client for Linux authentication domain list, desktop/application protocol list, and display list appear black on some Linux operating systems.

Because Horizon Client for Linux uses the Linux operating system's GNOME theme, these lists appear black, making them difficult to read.

Workaround: Change the GNOME theme used by the Linux operating system. For example, on an Ubuntu system, install gnome-tweak-tool if it is not yet installed, run gnome-tweak-tool , and change the GTK+ theme from Ambiance to Radiance.

• When client users connect to a published application using a multiple-monitor configuration, they may encounter unexpected behavior in the display if they disconnect or reconnect monitors in their configuration.

Workaround: Disconnect from the published application and reconnect again.

• Horizon Client does not support the Dark Appearance setting in Ubuntu 20.04.

Workaround: None

Keyboard and Mouse

• Mouse does not work inside the Horizon Blast session when the keyboard layout is switched to Secondary Keyboard Layout

Workaround: Manually add the following configuration option in the config file nested under /etc:

    RemoteDisplay.allowVMPointerEvent2 = FALSE

• Windows shortcuts don't work with seamless window applications.

If there are identical shortcuts with differing functions on the client Linux operating system and a remote Windows operating system, the shortcut for the Windows operating system will not work when a seamless window application is active. Only the shortcut for the Linux operating system takes effect. For example, by default, pressing Alt opens a Search dialog window on an Ubuntu operating system and it shows the application's menu on a Windows operating system. When a seamless window application is active, pressing Alt displays the Ubuntu operating system's Search menu, but does not show the application's menu.

Workaround : Change the shortcut in the host Linux operating system or in the remote Windows operating system so that the shortcuts in the two operating systems do not conflict.

• Keyboard and mouse do not work when connecting to a remote application from a Raspberry Pi running ThinLinX or Stratodesk.

There is a system conflict when using H.264 decoding with ThinLinX or Stratodesk Raspberry Pi for remote application sessions.

Workaround: Disable H.264 decoding in the Horizon Blast settings.

RDP

• If you connect to a remote desktop with FreeRDP and configure the desktop to connect to a separate disk, if the disk name includes non-ASCII characters, the disk name cannot be displayed correctly in the remote desktop.

For example, if you use non-ASCII characters in the disk name and then launch Horizon Client with command line option --rdpclient=xfreerdp and --xfreerdpOptions="/drive:, /home/user" the disk name does not appear correctly in the remote desktop.

Workaround: None

• If you use a FreeRDP connection and specify a monitor configuration that conflicts with the configuration the end user chooses, Horizon Client performance becomes poor and the client might stop responding altogether.

For example, the following command for launching Horizon Client would cause problems if the user selected Full Screen - This Monitor :

    [URI scheme] --enableNla --rdpclient=xfreerdp--xfreerdpOptions="/sec:nla /cert-ignore /p:password/u:crt\administrator /multimon"

Workaround: As a best practice, avoid specifying FreeRDP options for the display, such as /multimon or /workarea. Instead, let Horizon Client control the topology.

• Neither FreeRDP (xfreerdp) nor Remote Desktop (rdesktop) work on a client system running RedHat Enterprise Linux Workstation due to an Xorg error.

Workaround: Use the Horizon Blast protocol instead.

• Both FreeRDP (xfreerdp) and Remote Desktop (rdesktop) cause the X server to crash on client systems running Red Hat Enterprise Linux.

Workaround: None.

• Users cannot use rdesktop 1.8.x to connect to Horizon 7 Windows desktops.

This issue exists because Horizon 7 does not support TLSv1.0 by default and rdesktop 1.8.x supports only TLSv1.0.

Workaround: Enable TLSv1.0 on the desktop by setting the following registry key:

    [HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\SecurityProviders\SCHANNEL\Protocols\TLS1.0\Server]"Enabled"=dword:00000001

Be aware that TLSv1.0 is considered insufficiently secure. For Windows 7 desktops, Microsoft KB https://support.microsoft.com/en-us/kb/3080079 must also be installed.

• When using the rdesktop RDP client on a Red Hat Enterprise Linux machine to connect to a remote desktop, you cannot establish a TLS connection.

Workaround: None

Multimedia Redirection (MMR)

• Some video files might not play properly on a remote desktop when MMR is enabled.

Workaround : Make sure that the video format is supported and the proper decoder plug-in for the video is installed on the client.

• On a Windows 7 remote desktop, while playing video on Internet Explorer and then you open a new tab, the MMR video frame overlays in the new tab.

Workaround : Do not open a new tab or switch to a different tab while video is playing.

• Videos do not play smoothly in remote desktops and sound disappears when MMR is enabled and the network delay is more than 75 ms.

Workaround : Disable MMR when the network delay is more than 75 ms.

• When you connect to a remote desktop with MMR enabled and open a webpage that contains video content, the video thumbnail might not be displayed correctly.

This issue only affects the thumbnail display of the video, not its playback capabilities.

Workaround: None

HTML5 Multimedia Redirection (HTML5 MMR)

• When you open a local URL in Microsoft Edge on the remote desktop, multimedia content is not redirected to the client system as expected.

By default, HTML5 MMR in an Edge browser only works for content situated on a non-local URL. To redirect content from a local URL, you must configure a certain setting for Microsoft Edge.

Workaround : On the remote desktop, open a Command Prompt window and run the following command:

    CheckNetIsolation LoopbackExempt -a -n=Microsoft.MicrosoftEdge_8wekyb3d8bbwe

Application Sessions

• System Tray redirection functionality is not supported.
  System Tray redirection functionality is not supported so you can not exit a remote application session using the system tray.

  Workaround: Use the remote application's UI to end the application session. For example, to exit a Skype session, select the Settings icon and then select File > Exit.

• You cannot start an application from the Application Launcher because the launcher is unsupported.

  Workaround: Start the remote application via the Linux client's UI.

• System hangs may occur when using remote applications from a client system running Stratodesk.

  Workaround: Reduce the GPU memory to 128 MB. For example, in Stratodesk running on a Raspberry Pi, go to Configuration > Services > Raspberry Pi and change GPU memory (MB) to 128.

• When using Microsoft Teams Optimization Pack with Horizon Client for Linux published applications, screen sharing is not supported.

  Workaround: None.

Printing

• If multiple Horizon clients connect to the same published desktop or published application simultaneously and map to a location-based printer with the same name, the printer appears in the first client session, but not in later client sessions.

  Workaround: For the client sessions in which the printer does not appear, perform a manual refresh. For a remote desktop, press F5 or refresh the Devices and Printers window. For a remote application, close and reopen the application print dialog box. The location-based printer appears in the printer list.

Real-Time Audio-Video (RTAV)

• When a Raspberry Pi 4 client user tries to play RTAV video at custom high resolutions (such as 1280 x 800) not supported by the connected USB webcam, the video fails to display in the remote desktop.

  Workaround: Use a standard resolution that is supported by the connected USB webcam.

• When a Raspberry Pi 4 client user plays RTAV video at high resolution, the frame rate (FPS) of the video is low due to the limited CPU and memory of the client device.

  Workaround: None

Miscellaneous

• Issues when client system runs pcsc-lite version 1.5.
  Smart card removal policy may not work, logging off, shutting down or resetting a Windows remote desktop may result in a black screen, or the Horizon Client menu may become blank for about 10 seconds when a user has smart card sessions to multiple desktops and the user disconnects from one desktop.

  Workaround: Upgrade to pcsc-lite 1.7.4 or later.

• If you use a PulseAudio sound system, you might hear static when setting the volume using guest system volume slider.

  Workaround: Use the Linux client system's volume slider or use ALSA audio by adding sound.backendType = alsa to the config file nested under either the Home or /etc directory.

• When a RHEL 7 client user connects to a published Windows Server desktop using the Horizon Blast display protocol and attempts to log out from the session, Horizon Client might hang.
  This issue is caused by conflicting processes associated with version 1.8.8 of the PC/SC Lite (pcsclite) library.

  Workaround: On RHEL 7 systems, upgrade the pcsclite library to a version later than 1.8.8.

• Horizon Client crashes upon connecting to a remote desktop.
  This known issue occurs under the following conditions:

  • Horizon Client is running on an Ubuntu 20.04 system with Intel Ice Lake or later hardware, and
  • Session protocol is Horizon Blast with HEVC 4:4:4 encoding

  The Intel media driver that ships by default with Ubuntu 20.04 contains a bug that causes Horizon Client to crash. Later versions of the driver contain a fix for this bug.

  Workaround: Update the Intel media driver by installing the latest version of intel-media-va-driver-non-free.

Display

• On some HP thin clients that have the HP ThinPro 5.2.0 (T6X52011) operating system, Horizon Client for Linux might display a black screen or crash when user is playing some video on a remote desktop and pressing the fast-rewind button on Windows Media Player.

  Workaround: Upgrade the OS to HP ThinPro 6.1.0 (T7X61007) or the latest version.

• The Horizon Client for Linux authentication domain list, desktop/application protocol list, and display list appear black on some Linux operating systems.
  Because Horizon Client for Linux uses the Linux operating system's GNOME theme, these lists appear black, making them difficult to read.

  Workaround: Change the GNOME theme used by the Linux operating system. For example, on an Ubuntu system, install gnome-tweak-tool if it is not yet installed, run gnome-tweak-tool , and change the GTK+ theme from Ambiance to Radiance.

• When client users connect to a published application using a multiple-monitor configuration, they may encounter unexpected behavior in the display if they disconnect or reconnect monitors in their configuration.

  Workaround: Disconnect from the published application and reconnect again.

• Horizon Client does not support the Dark Appearance setting in Ubuntu 20.04.

  Workaround: None

Keyboard and Mouse

• Mouse does not work inside the Horizon Blast session when the keyboard layout is switched to Secondary Keyboard Layout

  Workaround: Manually add the following configuration option in the config file nested under /etc: RemoteDisplay.allowVMPointerEvent2 = FALSE

• Keyboard and mouse do not work when connecting to a remote application from a Raspberry Pi running ThinLinX or Stratodesk.
  There is a system conflict when using H.264 decoding with ThinLinX or Stratodesk Raspberry Pi for remote application sessions.

  Workaround : Turn off H.264 decoding in the Horizon Blast settings.

• Windows shortcuts don't work with seamless window applications.
  If there are identical shortcuts with differing functions on the client Linux operating system and a remote Windows operating system, the shortcut for the Windows operating system will not work when a seamless window application is active. Only the shortcut for the Linux operating system takes effect. For example, by default, pressing Alt opens a Search dialog window on an Ubuntu operating system and it shows the application's menu on a Windows operating system. When a seamless window application is active, pressing Alt displays the Ubuntu operating system's Search menu, but does not show the application's menu.

  Workaround : Change the shortcut in the host Linux operating system or in the remote Windows operating system so that the shortcuts in the two operating systems do not conflict.

RDP

• If you connect to a remote desktop with FreeRDP and configure the desktop to connect to a separate disk, if the disk name includes non-ASCII characters, the disk name cannot be displayed correctly in the remote desktop.
  For example, if you use non-ASCII characters in the disk name and then launch Horizon Client with command line option --rdpclient=xfreerdp and --xfreerdpOptions="/drive:, /home/user" the disk name does not appear correctly in the remote desktop.

  Workaround: None

• If you use a FreeRDP connection and specify a monitor configuration that conflicts with the configuration the end user chooses, Horizon Client performance becomes poor and the client might stop responding altogether.
  For example, the following command for launching Horizon Client would cause problems if the user selected Full Screen - This Monitor : [URI scheme] --enableNla --rdpclient=xfreerdp --xfreerdpOptions="/sec:nla /cert-ignore /p:password/u:crt\administrator /multimon"

  Workaround: As a best practice, avoid specifying FreeRDP options for the display, such as /multimon or /workarea. Instead, let Horizon Client control the topology.

• Neither FreeRDP (xfreerdp) nor Remote Desktop (rdesktop) work on a client system running RedHat Enterprise Linux Workstation due to an Xorg error.

  Workaround: Use the Horizon Blast protocol instead.

• Both FreeRDP (xfreerdp) and Remote Desktop (rdesktop) cause the X server to crash on client systems running Red Hat Enterprise Linux.

  Workaround: None.

• Users cannot use rdesktop 1.8.x to connect to Horizon 8 Windows desktops.

  This issue exists because Horizon 8 does not support TLSv1.0 by default and rdesktop 1.8.x supports only TLSv1.0.

  Workaround: Enable TLSv1.0 on the desktop by setting the following registry key:

  [HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\SecurityProviders\SCHANNEL\Protocols\TLS1.0\Server]"Enabled"=dword:00000001

  Be aware that TLSv1.0 is considered insufficiently secure. For Windows 7 desktops, Microsoft KB https://support.microsoft.com/en-us/kb/3080079 must also be installed.

• When using the rdesktop RDP client on a Red Hat Enterprise Linux machine to connect to a remote desktop, you cannot establish a TLS connection.

  Workaround: None

Multimedia Redirection (MMR)

• Some video files might not play properly on a remote desktop when MMR is enabled.

  Workaround: Make sure that the video format is supported and the proper decoder plug-in for the video is installed on the client.

• On a Windows 7 remote desktop, while playing video on Internet Explorer and then you open a new tab, the MMR video frame overlays in the new tab.

  Workaround: Do not open a new tab or switch to a different tab while video is playing.

• Videos do not play smoothly in remote desktops and sound disappears when MMR is enabled and the network delay is more than 75 ms.

  Workaround : Disable MMR when the network delay is more than 75 ms.

• When you connect to a remote desktop with MMR enabled and open a webpage that contains video content, the video thumbnail might not be displayed correctly.
  This issue only affects the thumbnail display of the video, not its playback capabilities.

  Workaround: None

HTML5 Multimedia Redirection (HTML5 MMR)

• When you open a local URL in Microsoft Edge on the remote desktop, multimedia content is not redirected to the client system as expected.
  By default, HTML5 MMR in an Edge browser only works for content situated on a non-local URL. To redirect content from a local URL, you must configure a certain setting for Microsoft Edge.

  Workaround : On the remote desktop, open a Command Prompt window and run the following command:

  CheckNetIsolation LoopbackExempt -a -n=Microsoft.MicrosoftEdge_8wekyb3d8bbwe