I have the exact same issue.
Please note the "AD Server Users List" pop-up page works and is fully populated.
When a user is selected for import and "Save" is pressed:
* no error message appears on the screen.
* the user is not imported
* the error log shows the NULL not allowed for user password sql error described in the previous comments.
Please note: I've been monitoring my host's network connection for ldap transactions and see the queries that generate the "AD Server Users List" dialog. No further queries are produced when attempting to import a user.
This appears to be a database not LDAP error to me. We are still in evaluation and are using the embedded H2 database. We're using razuna version 1.8.6.