hello there...
unfortunately the problem is still unsolved - i am writing with the vmware support for a few days. the first awareness has been: yes, that is correct - you can not use flr on a dc! so far, so bad...
know the ticket has been elevated to an escalation engeneer and they check if they are able to involve further experts (maybe a software developer - who knows ^^).
but no suitable solution so long (besides using advanced login from another backuped vm within the same realm) - will keep the thread uptodate 