Resolution:
For a damaged(corrupted)  Administration domain, its registered WF server and Repo server will not be able to unregistered from domain utility, and therefore will not be able to be added to a new domain.


The reason that these two old servers can not be added into the new domain is because their mapping information are stored in the file:
tibco\tra\domain\ IcServers.properties

For example, I have a WF server “ad2”, and a Repo server with port 9011 registered in domain “ore98-2”.
Then in this file, I can find the following lines:

ad2-9011.domain=ore98-2
ad2-ad2.domain=ore98-2


Once these two lines are removed, then the old servers should be able to be added into the new domains.