I am using the steam version of the game if that makes a difference.
I have several times submitted a problem report through this website's support system and no one ever replied to me. So I am very unhappy with the support for this problem.
You would think that Crytech and EA would want this problem fixed asap as they are losing sales because many people are being stopped from purchasing the DLC due to this purchasing problem. I have two pc's at my house and I was going to purchase 2 copies of Crysis 2 and all the DLC on both pc's so that me and my friends could play. But since I can't even purchase the DLC on my first pc, I am not going to purchase the 2nd copy of Crysis2 for my othe pc. So in my case, EA and Crytech has not only lost the sale of DLC, but also lost the sale of a second copy of the game. there are many others on this forum reporting the same problems. Please EA and Crytech, fix this!
This is very frustrating and part of the reason for the lack of players playing the DLC for this game.