Cubase 10 Pro corrupts project

Hi everyone!

I had to projects open and I wanted to activate the other project. After clicking the “lightning button” to activate the inactive project Cubase froze.
I clicked Ctrl/Alt/Del and terminated Cubase. After I tried to open the project that was first active I get a “Serious Problem” -warning that starts to cascade again and again. This doesn’t happen with any other project but it happens to the corrupted project’s backup too.

I’m sinking into desperation. :frowning: Can anyone help and/or has this happened to anyone else? :question: