This is happening to me also. Checked my Plus subscription and it’s good until August 2021, but when I try to log in ESO it gives the ERROR LOADING PROFILE message.
Additionally, PSN is displaying “undergoing maintenance” messages when trying to do other things (like trying to extend Plus before checking how long before it resubscribes me). I see only PlayStation Video as having outages when checking the PlayStation connectivity page.
Yesterday the PSN was experiencing issues leading to login issues on the PS4 megaservers. These issues should now be resolved. For this reason we are closing out this discussion. If you still have login issues please go ahead and start a new thread for help.