Disable category domain controllers

In opmanager 6 is a new category named Domain controllers.

When i add a domain controller - he was standard in this category - ok fine. But when i change the category to server (because i don't see any information in cause of the not licensed addin) every few minutes he changed back to domain controller!!! Can i disable in any way the category domain controllers?

Is it possible that windows has to do with that problem?

This message is from the eventlog on opmanager-pc:
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DCOM was unable to communicate with the computer 192.168.9.9 using any of the configured protocols.
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Thanks,
martin