I have exactly the same problem.
I bought the game, downloaded it and all worked fine. After 15 minutes I saved my session and exited the game. A few hours later when I tried to load and play the game i got the "Failed to start game (missing executable.)". I tried all the advice in the support link, uninstalled, cleared cache, etc, etc.
I did notice after having re-installed the game 3 times that the actual download of the game takes less than a second and when you look at the download manager you can see that the game is "downloaded" but no bytes have been downloaded.
What is wrong??? Someone please help.
