The tip definitely put me on the right track. Until recently, I was still running PHP 7.4 and the "MemberMap" app. After the recommendation in the ACP to finally switch to PHP 8.0, I did so. After that, however, the forum was initially blocked (access to the ACP, however, was still running). Eventually I found out that the "MemberMap" was the culprit. After I deactivated them, the forum ran again. So far so good.
As you pointed out, I checked the system logs. To my amazement, there were still reports about the "MemberMap". Then I tried to uninstall it. However, this also led to the same error message as when the user in question logged in. The solution was to first change PHP to 7.4, then uninstall the app and finally back to 8.0. However, why the problem only occurred with this one user and, as far as I know, with no other ... I have no idea.
Thank you for your hint!
I would suggest first of all checking your server error logs to see what the actual error is. If you are getting an internal server error, then this is where it would be logged.
Also, disable all 3rd party items and test the same
@Kazhal modsecurity (if it is used) can do this if the username is any of the mysql commands or a substring of a known bad useragent string.
https://xkcd.com/327/
Kazhal got a reaction from Randy Calvert in Cursed User?!
Kazhal reacted to Marc Stridgen in Cursed User?!
