Crysis 2 will be getting a patch pretty soon to fix some of the problems they’re experiencing in multiplayer.
Crytek has also suggested a workaround for the multiplayer issue in which the game repeatedly requests the player’s serial number to play multiplayer or get the (erroneous) message that states, “Serial number in use”.
The three step method requires the player to:
* Load Crysis 2, go to multiplayer and type in your key * Navigate back to Single Player * Go back into multiplayer and re-enter your key
* Navigate back to Single Player
* Go back into multiplayer and re-enter your key
This apparently saves the key into the software. This won’t fix all of the problems, especially the “code already used” message, or the crashing and freezing, but it’s one annoyance out of the way.