When tried to refresh in BizTalk admin console, keeps complaining schema referenced map has been deleted, The local, cached version of the BizTalk Server group configuration is out of date. You must refresh the BizTalk Server group configuration before making further changes

Due to some schema namespace change, and don't want to re-do the maps, so I openned the map in XML edit mode and updated the namespace. Then when I tried to deploy the solution, It failed.
And I am getting the error as the title indicated.

There are some missing or isloated maps data in the database to be cleaned.
In the BizTalkMgmtDb database, look up the bt_mapspec table, delete the map entry for the one the administrator console complained.

And referesh, then it worked.