"Unexpected exception when initializing view part Coincidencias de fragmentos"

Hi,

All of a sudden, I can't use Studio 2021.

When I try to open a file to work on it I get the error message above, I can't open the file and also Studio gets frozen. I can't even change the area (from Files to Project or the Welcome area. I need to close Studio if I want to change the area I'm working on.

I can create a new project and also pre-translate it, but I can't work on it.

Can any of you help me?

Thank you

Marga