I noted the other topic referencing the MS .net update negative impact on FTM 2012's ability to load. I'm running Win XP and thought I'd verify the problem.
Upon starting FTM 2012, I was immediately presented with an update. After the update was applied, FTM loaded successfully.
However, the 2 prior existing linked trees no longer appear in my FTM "Tree" list while the 2 online "Member Trees" are still listed as being linked to FTM.
Quite a mess now to deal with.