[Mailman-Users] Signup problems with MM2.0.13

[Christoph Wille]

I get lots of such error messages:

**************
An unexpected Mailman error has occurred in
MailCommandHandler.ParseMailCommands().  Here is the traceback:

Traceback (innermost last):
   File "/home/mailman/Mailman/MailCommandHandler.py", line 235, in 
ParseMailCommands
     self.__dispatch[cmd](args, line, msg)
   File "/home/mailman/Mailman/MailCommandHandler.py", line 633, in 
ProcessConfirmCmd
     self.ProcessConfirmation(cookie)
   File "/home/mailman/Mailman/MailList.py", line 1035, in ProcessConfirmation
     self.ApprovedAddMember(email_addr, password, digest)
   File "/home/mailman/Mailman/MailList.py", line 1042, in ApprovedAddMember
     digest, ack, admin_notif)
   File "/home/mailman/Mailman/MailList.py", line 1137, in ApprovedAddMembers
     digest)
   File "/home/mailman/Mailman/Deliverer.py", line 35, in SendSubscribeAck
     if self.welcome_msg:
AttributeError: welcome_msg
**************

How can I find out what exactly caused the problem?

Chris