Try verifying the game cache.
In Steam, go to View (Top Left) then click on Games Details. In your list, right click FM2013 and select "Properties". Click on the Local Files tab and then the verify button is there.
What this does is check your FM2013 installation, it then will fix and redownload files if it sees that the game is missing any or is not up to date. It's worth noting that during busy periods, this process sometimes needs to be done more than once.