OM12 Installation Issue: Additional OM12 Management Server Won’t Install Because The Dropdown Box On Database Name Is Empty

Since I bumped a few times into this issue (but always solved it) I want to share this experience with the community.

Issue
When installing an additional OM12 Management Server (besides the first OM12 Management Server), one has to select the SQL Server which hosts the OperationsManager database. Selecting the SQL Server itself goes fine but the dropdown box is empty. No way you’re allowed to type in the name of database itself. Like this screen which I created in order to show what I mean:

This issue can also happen when installing a third/fourth/fifth and so OM12 Management Server…

Possible Causes
Screens like these are no fun. Many times people tend to look at the SQL Server. But until now, when I run into the above mentioned issue, it wasn’t the SQL Server itself. Nor a network or a firewall issue. These were the causes I bumped into:

1. The server which had to become an additional OM12 Management Server had an OM12 Agent installed. This Agent was removed from the server before the OM12 Management Server was installed.
   
   Remedy: In this case the OM12 Agent was still present in the OM12 Console and listed (as unmonitored) under the Agent Managed node (Administration > Administration > Device Management > Management Servers).
   
   Simply removed the particular Agent and reran the installation of the OM12 Management Server which just run without any issues now.
   
   
2. The server which had to become an additional OM12 Management Server was an OM12 Management Server before but turned sour. OM12 was neatly removed.
   
   Remedy: In this case the OM12 Management Server was still present in the OM12 Console and listed (as unmonitored) under the Management Servers (Administration > Administration > Device Management > Management Servers).
   
   Simply removed the particular Management Server and reran the installation of the OM12 Management Server which just run without any issues now.

As you can see, many times there is a lag between reality (no more Agent or Management Server presence on the troubled server) and the OM12 database. Just check (and double check the Console) and many times you’ll find that server listed as an unmonitored OM12 Management Server or OM12 Agent. When in doubt check the node Agentless Managed systems as well. Remove it and you’ll be fine.