Bumping this as I am having this problem today - full error message "The server has been unable to validate your details. Please contact the support forums at.." I've tried restarting etc and have had the error off and on over about a 10 hour period. Edited to add: I own the game via steam...

Hi, I've been having the same issue, since about 8:30am this morning (Australian EST). The error occurs when I try to log into MultiPlayer (on the credentials screen). After I click OK, the the program takes a while and then gives me the error message "Corrupt or invalid response from server&qu...