Dnspy: Debug Error when trying to attach to Process - Debugging is not possible due to an incompatibility within the CLR implementation

Question

I want to debug a running process to get some internal informations in a DotNet Tool. I've opened the Exe-File in Dnspy and have set an break point at the position I want to take a look. Then I've tried to attach to a running Process. Unfortunately I got the following error message::

Debugging is not possible due to an incompatibility within the CLR implementation (0x80131346)

The CLR from the running process is CLR v4.0.30319. I've done debugging in same way many times before and I've no idea what I can do. Does anyone know this problem and can help me to solve it

Thanks you very much.
Kind regards

Markus