User creation fails

[JP Horst]

I set up kolab 3.0 on centos and created several user with disabled recipient policy (as described in the manual).

In the meantime I updated to kolab 3.1 and want to create another user:

I choose kolab-user fill all fields out and then get a message, that not all necessary fields are filled out. It looks as if on the 5th tab ("Andere-Other") there is a field labelled "user.u201cmailu201d", which needs to be filled out (and which is not documented in the manual).
If I just type in anything in this field, this solves the first error message but produces another message "Internal error".

/var/log/kolab-webadmin/errors shows the following error message:

PHP Warning:  ldap_add(): Add: Object class violation in /usr/share/kolab-webadmin/lib/ext/Net/LDAP3.php on line 222


Existing users do not have any entry in this field. However, I cannot modify these users either.

Does someone know, how I can solve this problem aka what to type in this field?

Thanks for any help
Jens-Peter