Game is not running

[Kurisu]

I have registered my Product Key on these forums so i know the code is valid, however when i start to play the game, it simply comes up with the Steam dialogue saying "Preparing to launch prison architect" and it never launches. The dialogue will close, and seconds later reappear.

Before this it would give me my product key, and tell me to put it in the game when the games asks for it, but i played the game for 3 hours yesterday and it never once asked for the key, it is only since i have come to play it today that this has happened.

I cannot put the product key in the game because the game does not play.

[intertoothh]

Same problem here.