Error de-activation (multiple instances)

Hi, 

I have problems de-activating my second Trados Studio Freelance 2021 version. I am receiving an error message stating that there were multiple instances running but they are not.

Multiple instances of this application are running.

Please close these other instances before you de-activate your license (paraphrasing since the error message is in German).

The first computer is off and I can't even submit an offline de-activation form.

How shall I proceed further?

Looking forward to your response.

Regards,

Raphael.