I was able to pin down the issue to the second monitor now.
I can open any plug-in within the effects rack just fine. As soon as I move the effects rack to the second monitor and I try some critical plug-ins (e.g. NI Raum or Super 8), Cubase shows a white Plug-In Box without content and the music keeps playing but everything else is freezed.
Sombody else experiences the same issue and found already a solution?
Not quite sure when it started, but I think around 2 days ago. I installed the update to 12.0.10 five days ago.
In between I made a Mobo-Bios-Update. Nothing else. Also I made sure that I took over the same bios settings.
Is the other screen (where it doesn’t happen) the Main screen? Do you have the latest driver installed? How are the 3 screens connected (are there 3 HDMIs)? Does it happen, if you connect only 2 screens?
as I wrote above, when I’m doing it on just the main screen, everything is working fine. As soon as I try to open the plug-ins on the second screen. It will freeze. I updated once again the graphics drivers but nothing changed. I will try what you recommended below and get back to you.