Had the problem for the very first time 3 days ago. Solved it by uninstalling various .NET framework updates (KB5012117, KB5010472) and preventing them to be reinstalled by using the "wushowhide.diagcab" tool from Microsoft.
This problem just cropped up for me. My guess is you guys glued down this issue and Microsoft through .NET update unglued it for you. I'll keep this thread subscribed to see if you guys are able to glue it down again.
Could you please try updating both Host and Viewer to the most recent version 188.8.131.52 and see if this helps to fix the issue? You can update your Host and Viewer using the Simple Update feature. In addition, please make sure that your Host and Viewer are both updated to the same version and there's no version mismatch because it might lead to some features not working or other performance issues.