You can connect to the server by SSH connection using default port 22222. Please refer to the manual on how to achieve this. If you still are not able to add users please send logs to support@open-e.com
I have got an answer of your support team today. There was a problem with LDAP server. I must change for a moment to ADS or PDC and then back to LDAP. That was the Solution. Now i can create user an groups.
Thank you for the good and fast support from her and from your support-team.