"Unknown error see supervisor" when trying to backup

Hi Guys, new at this great tool
Have been using HA in a PI3 to get familiar with the system, have connected some sensors and quite well got it working, however the PI3 is slow, so i thought i´d install a PI4
Now following the instructions online i wanted to make a backup copy, however the system will not let me do this at all, it just comes up with “Unknown error see supervisor”, what where when???

Have installed Terminal and NSpanel, nothing else - have some shelly devices running but otherwize i have not done any advanced programming on the thing yet

Looked online, but what is supervisor, and do i even have it installed??, updated to the last version HA yesterday

Any of you guy´s know whats up?

Best Regards
/ Andy