Crone failure chrooted passwd?

I got a failure from crone and don’t know how to handle this. To me sa testuser are autoresponders coming:

https://list**/admin/?page=processqueue&secret=bcc1b4c1*******ef83ee" wurde in 0 Sekunden abgeschlossen, jedoch traten Fehler auf**

user with id=10626 and name=istok not found in chrooted passwd file
system error: No such file or directory