[Solved] Error running script 97univention-s4-connector.inst on backup2master and upgrade

Friends once again I here. In one of my environments I had the local UCS Master and an external UCS Backup. After a problem with the master I followed the tutorial: http://docs.software-univention.de/manual-4.4.html#domain:backup2master and converted the backup to a master. The problem is that during the process the following error occurred:

Running 92univention-management-console-web-server.inst skipped (already executed)
Running 96univention-samba4.inst skipped (already executed)
Running 97univention-s4-connector.inst failed (exitcode: 1)
Running 98univention-pkgdb-tools.inst skipped (already executed)
Running 98univention-samba4-dns.inst skipped (already executed)
Running 98univention-samba4-saml-kerberos.inst skipped (already executed)
Running post-joinscripts hook (s): done

My question is whether this error can cause problems up front in my UCS and if so, how can I debug what is causing the s4-connector to give an error.

PS: At the moment I only have the new UCS master, so I intend to make sure everything is correct, add a new UCS backup in the place where the old master was.

PS2: The 97univention-s4-connector.inst script is taking about 5 minutes to run at each attempt, even though it is on a VM with SSD and low processor usage.

After removing all DNS entries from srv-adds01 (the old server), I was able to run the script without any problems.