Oops! An error occurred while attempting to create the server

This error message I get any time I try to run a server.

Firefox 95.0.1 (64-bit)
Ubuntu 20.04.3 LTS (Focal Fossa)

do you already have 3 servers? did you try to log out and login again?

Logout and login again helped, thanks.
Should I explore this issue more, to find repro and so_?

no, it is not something that you can investigate, I think that the session expired and it was only needed to login again