Attention of those who recently bought S.T.A.L.K.E.R.: Clear Sky on STEAM and experience problem activating/running the game. Due to technical mistake, the CD-key you received is non-working. To solve the problem, please, follow the link below where you check and change the old key with a new working one. https://stalker-game.com/cdkey/

On behalf of GSC Game World, we would like to apologize for any inconveniences caused.