New row violates row-level security policy for table "projects"

[gniederlaender]

I managed to install the self-hosted version, but when I try to send a request, I get the message:
"new row violates row-level security policy for table "projects"".

It seems to be an issue in user management, correct?
Do I need to register a user on localhost, like in the "normal" mode? This did not seem to work for me flawlessly as well.

Database seems to be in place, up and running.
Any ideas?