Anyway to fix without reinstalling

Been playing FM2009 without major issues since mid November. Was playing it earlier today but then I had to head to work so I turned off my laptop and packed it with me. Just now I decided to play a few games to pass some time and get hit with the request to activate the game. I bought the game through steam and I have tried to run it through steam and without steam started and both gives the same. The only tip I have seen sofar is to reinstall the game but that will take a lot of time and I have a limited trafficquota on my mobile connection so patching will be horrible. Is there anyway to fix this without reinstalling?

Anyone that have had this problem and managed to fix it with or without reinstalling? The only tip I have found is to reinstall but if the chance is slim to none to get it working I don't want to waste my limited bandwidth downloading the patches again.