Charm - Setup of TMS - Error Transport Routes

Hi experts,

I want to setup the TMS in Charm.

I've already maintained the RFCs via solman_setup.

However, in transaction SOLAR_PROJECT_ADMIN I get the following error:

"Incorrect RFC connection  to domain controller <SID> 000"

Error number is /TMWFLOW/TRACK_N193

Does anybody know what the problem might be?
I didn't really find a solution for this on the internet.

Kind regards