Mailman Cron Messages

[arwed]

Hi,
sorry but I'm new to Plesk and mailman.

Every 5 minutes I keep getting this message in my emails:

Subject: Cron <mailman@s15170565> /usr/bin/python -S /var/mailman/cron/gate_news
X-Cron-Env: <SHELL=/bin/sh>
X-Cron-Env: <HOME=/var/mailman>
X-Cron-Env: <PATH=/usr/bin:/bin>
X-Cron-Env: <LOGNAME=mailman>

Traceback (most recent call last):
File "/var/mailman/cron/gate_news", line 274, in ?
main()
File "/var/mailman/cron/gate_news", line 254, in main
process_lists(lock)
File "/var/mailman/cron/gate_news", line 189, in process_lists
mlist = MailList.MailList(listname, lock=0)
File "/var/mailman/Mailman/MailList.py", line 101, in __init__
self.Load()
File "/var/mailman/Mailman/MailList.py", line 588, in Load
raise Errors.MMCorruptListDatabaseError, e
Mailman.Errors.MMCorruptListDatabaseError: [Errno 2] No such file or directory: '/var/mailman/lists/mailman/config.db.last'


What did I do wrong?
Please Help.

Regards
Arwed