Hello. I am new to this site. For several days I tried to connect to a server and always get the same errors: invalid serial, diconected from server (or such thing) or serial already in use. How can I play in multiplayer? Must the serial contain only letters/numbers or the serial must be the serial used for installing Crysis 2 ? Can someone give me an Idea on how to fix this and an example of a valid serial ? Sorry if I did something wrong. Version of game: 1.1.0.0