Hi Michal,
i have similar problem.
Last weekend, my environment went down for maintance, since then, I can't add applications, can open existing modules but can't publish them because of compile error, and can't run any applications, for example not even users application.
I have a support case opened, but at first glance, they couldn't see anything wrong.
Since I can't run applications, I'm guessing it's a problem in the personal environment rather then service studio.
Also in Service Center, there are many error logs
I'll update here if there's any progress
This is for example what i see, instead of choice for type of application

Dorine