Windows 10 hangs after upgrade from version 15 to version 16

Today, November 1, 2020, I purchased, downloaded and installed the version 15 upgrade to Parallels Desktop 16 for Mac. After starting this up, the Windows screen appeared quite quickly, which to my surprise and disappointment I could not do anything with. It turns out to be a dead Windows screen where I cannot activate any app. The mouse pointer moves freely on the screen, but I cannot click to open anything. Even closing the Windows screen is not possible immediately because the program does not respond to this either. Does anyone have any idea why this is and how this problem can be solved?
Paul S

 

Hello did you try to reinstall Parallels Tools, restart your Windows VM and check the issue?