I think I had the problem you are having when they released the update. If you do a search for instructions on how to verify your local cache it can fix it, but short version is;
go to game library in steam
right click FM2012, select properties
select local files, click verify integrity of game cache
this fixed my issues when it kept telling me the game was unavailable and allowed it to update properly
go to game library in steam
right click FM2012, select properties
select local files, click verify integrity of game cache
this fixed my issues when it kept telling me the game was unavailable and allowed it to update properly