I get this error:

Kein Profil für die folgende Benutzernummer vorhanden: 322 at /home/www/web2/html/cgi-bin/ubb_lib_files.cgi line 1047 main::OpenProfile() called at /home/www/web2/html/ubb/Templates/public_pntf_summary.pl line 919 main::QuickSummary() called at /home/www/web2/html/cgi-bin/ubb_lib.cgi line 1688 main::FilterPNTF() called at /home/www/web2/html/cgi-bin/ubb_lib.cgi line 1621 main::ServeFromCache() called at /home/www/web2/html/cgi-bin/ubb_forum_summary.cgi line 112 main::forum_summary called at ultimatebb.cgi line 646

What is this, what can I do?

Have you rebuilt the stats, etc. in the CP?

Yes, it ist in recent Visitor problem, I have deleted now the recent visitor rekord and now it works...

Yeah, I've see that many times. It's gotten to the point where we don't delete members anymore (my webmaster likes his visitor record)