Receiving - The Remote Desktop Service ActiveX control (mstscax.dll) does not match the version of the client shell.- error on application launch attempt

Receiving "The Remote Desktop Service ActiveX control (mstscax.dll) does not match the version of the client shell." error on application launch attempt


When attempting to launch your RemoteApp (either from the AppDashboard, or the Web Portal), you receive the following error message:

Latest Update: 02/14/2023


A patch from Microsoft has now been released. The KB reference has changed since the internal release, and it is now included in the following KB: KB5022360 (Which is an optional preview)

As of 02/14/2023, KB5022845 has been released, which will install as part of the regular Windows updates. Users who are facing an issue, should make sure to apply all available Windows Updates are installed, which should include KB5022845, and the issue will be resolved.

For additional updates and details on this issue, please see the advisory


This message happens if you had previously applied a patch for the 22H2 Bug and then applied additional Windows updates after installing the patch. This renders some file versions mismatched in their version which causes this error. 


We have created an update version of the FixMSTSC utility which restores the original files, and applies a less intrusive workaround. 

You may download this patch by clicking below. You must run this utility as Administrator, by right-clicking then select "Run As Administrator". If your computer is locked down, you may require your IT department's assistance to run this utility. 


You can read more about the workaround, and how to restore your settings when Microsoft releases the permanent HotFix for this issue in the fourth week of January 2023.