If you still have the problem, get in to the EA support, though they had not yet received a solution, but they answer, at least, and work on the problem
Sorry for my bad English

I have the same problem too.

Same here.

contacted the EA support to at least try to help, I hope there is enough, the report noted that it affects many players

31/3 - Today we released the first of a number of security updates, accounts that we have identified as exploiting an unfair advantage have been reset and if the activity persists they will be banned permanently. If you find yourself being kicked from every MP game it is because our systems have detected you cheating. We will continue to update anti-cheat software in Crysis 2 and strive for a cheat-free community.

- CryAdam




Is there a possibility that their anti-cheat system is affecting non-cheaters as well???
This could be the case.

Is there a possibility that their anti-cheat system is affecting non-cheaters as well???
This could be the case.
No because this has happened since day 1 and also the demo (beta stage 1) for me and many others before Crytek even contemplated implementing an "anti cheat" system. I mean, how long does fixing a server issue take? No wonder there are so many bugs in this game (apparently) if Crytek can't even get the basics right!!! I am still yet to complete a single MP match before "lost connection to host, returning you to the login page" rears it's head!!!

How about the firewall?

The other players could be using strict firewalls...

I got the message twice yesterday. My NAT is "moderate".
I had two really good runs when it happened with almost no deaths.
Never had it before.

I have this message as well
So annoyed!

Hope Crytek fix this bug!