We fixed a bug where it was impossible to change passwords via the UMC due to the UMC server not closing file descriptors properly. Please check if an update might fix the problem.
Problem
When trying to change the password via the web interface (UMC) some or all users are constantly getting an errorcode 20 message.
Solution
This issue might be related to a bug. To fix it temporarily restart UMC: systemctl restart univention-management-console-server
Once verified and the issue is not gone, consider to check these articles as well:
