I think we have a problem with the new join hooks if a broken univention-join-hook of type join/pre-join or join/pre-joinscripts is registered in LDAP. This was just the case with a developing join hook from UCS@school: In case of a faulty hook script (exitcode != 0) univention-join aborts the join process before executing the join scripts. For an app that is installed on a non-master, however, the join script is the only place to replace the defective join hook with a working variant. This means that if the join hook is broken, the app cannot automatically repair it with an app update. I think we need an idea for a solution here.
This issue has been filed against UCS 4.4. UCS 4.4 is out of general maintenance and components may have vastly changed in later releases. Thus, this issue is now being closed. If this issue still occurs in newer versions, please use "Clone this bug" or reopen this issue. In this case please provide detailed information on how this issue is affecting you.