The specified service user either does not exist or is not configured as a service user in the Release Management server. ...

The specified service user either does not exist or is not configured as a service user in the Release Management server. To perform the necessary changes, the user running the configuration tool needs to be a valid Release Management user with "Release Manager" permissions.

Please re-run the configuration tool using a Release Manager account or have a Release Manager manually add the service user using the Release Management Client and try the configuration again.