Univention UCS 4.2 - Failed 'Active Directory Takeover' process - Troubleshooting

Yes, my bad. Next time I will reply myself when figure out an answer for my own question. I just highlighted the solution to be easier for others to read the solution.

By the way, do you have any idea on how can I troubleshoot my other problem?

You are the first person I can interact with on this forum after about one month here.

Kind Regards!