[TYPO3-german] Can not Login in the BE

[Robert Wander]

Hey Everyone,
I'm new on this list, and if it wouldn't be my productive-system I wouldn't
ask so "fast".

Does anyone know a solution for this problem?

Update from 4.5.10 to 4.5.11.
Login and clearing Cache.
So far,,,
but while clearing the Cache my DB and the whole webserver freezed.
I Restarted mysql and apache via cmd
but nowI didn't get access to the BE again, but in the sys_log I get: "User
%s logged in from %s (%s)" but on the Page I get
"Ihr Anmeldeversuch war nicht erfolgreich
Bitte stellen Sie sicher, dass Ihr Benutzername und Passwort korrekt sind.
Groß-/Kleinschreibung wird unterschieden."

Allready cleared all caches by deleting temp and all temp_CACHED files,
also gut a new encryption key... but nothing...

Allready rolled back the sources to 4.5.10 but no changes...

Does anyone have a good idea to solve this?

Greating Robert