I played the game just fine for a couple hours straight. For no apparent reason, my connection to the server dropped and I got an error message reading: "The Connection to your Session has Been Lost."

Now I get this message about every five minutes. It's making it impossible to play multiplayer.

Any ideas what's causing it? Again, the game worked fine for a few hours straight, and this happened out of the blue.

bump

I'm getting the same problem! Haven't been able to play a single MP game yet. I don't get this problem with any other MP game and my internet is fine. Anyone have any ideas how to fix this problem?

[edit, bump] This is STILL TRUE FOR VERSION 1.2 patch of Crysis 2 on PC.
--
Crytek take note for PC version 1.1 of Crysis 2:

Cannot play multiplayer games, period. Get kicked out of each and every server within 10 seconds of a game starting, no matter what server, what map, what machine or legal copy of the game I am using. Bought a couple of copies, installed on different machines, none work. Single player, no problem... Multiplayer, no way.

First, on a fresh install I get this the very first time I try to play multiplayer:
'Invalid Parameter' in server browser with a fresh install before even getting into the first multiplayer game (after fixing key-stick issue by going Single player then Multiplayer). Looks really bad when the first thing that happens out of the box after you freshly install the game to a new machine and patch to version 1.1 and then run the game for the first time, you're met with a bug. The words "not ready for release" come to mind.

More importantly, I bought a couple of copies of the 'Limited Edition' (haven't gotten to start a multiplayer game in 24 hours so haven't gotten far enough to get any of that either) and am unable to get ANY of them to play a multiplayer game on any machine.

I get disconnected with a "Connection to your multiplayer session has been lost. Please check network connectivity. Returning to Main Menu". This happens when I'm past the lobby in a game map, past the class choice, already spawned, playing on a PC with a fresh install.

Then I sometimes get "The connection to your opponent has been lost. You've been signed out.", sometimes followed by a "Signing out. Please wait." which takes me all the way out to the login screen.

Crysys 2 says I have a "NAT type: moderate".

The 'console' log says...
disconnect cause 11 ... msg "Nub destroyed."

When I get disconnected while in the Lobby waiting for game to start, the console says:
SessionDelete error 0
CryFixedArray removeAt() failed as i=-1 is out of range of curSize 14
Lobby EndTask 18 (18) error 17

Console also says somewhere UserGetPurchaseHistory error 28

another one says
CryFixedArray removeAt() failed as i=-1 is out of range of curSize 15

So, don't know what any of this means. All I know is I bought several copies of the game and they DON'T work, on different machines.
No Multiplayer at all.
I can log-in.
I can see servers.
I can join servers.
But I *ALWAYS* get disconnected.
???

Not good, Crytek. Disabled Microsoft antivirus. No firewall. Still not working. Seems it's Crytek's problem, not the machine.

By the way, on this same network, same PC machines, I can play CoDMW2, CoD Black Ops, L4D2, Bloodline Champions, LoL, Need4Speed, HoN, Team Fortress 2 and dozens of Steam games. What gives?

This is my story EXACTLY. Not a thing is different for you than me.

I just want some answers.

Crytek better fix this **** and fast.

a-men this is my life I've done everything humanly possible to fix the connection issue and nada...

I have the exact same problem! The campaign was incredibly easy so I've tried playing multiplayer pretty much since the release and I've played about 3 full length games so far

this is stupid same happens to me...invalid parameter i mean WTF!!!
campaign=ALL GOOD!!
multiplayer ==NOT ALL GOOD!!!
also whenim playing and i try to join a 15/16 full server it says server full.....
riddled with problems but if they are fixed quickly then ill forgive...;D
Just tell me what to do!!!!!!!!!!!!!!!!!!!!!!

So many post but i can't find any relating directly to lost connection to multiplayer session.

Cry-admin

Please fix or give me something to work with
It's not my system,
It's not my broadband,
It's not my portsettings,
It's not my fault,
I am still rank 6, Why? because i can't play this game online

Are you working to resolve this or compensate me and other gamers for wasting my time trying to play the last 45 seconds of a round to try and reach the top of the leader board with the limited kills you can gain in that time?
What is the point of a leaderboard, what assistance is there other than this forum I would like help to identify why some can play full games and others, well... just get frustrated. I will not buy anymore games until i am fully aware that they have been tested and all the issues ironed out.

If this sounds familiar to any other pc gamers out there please sign your name below

If anyone (inc. Dev) has a solution or idea how to solve this please also post below.

This post hopefully is to keep some order in this ever growing forum.

[Bump.]

It's been a week, still no way to play multiplayer. Hello Crytek?

There's really 2 problems here:
#1) That this game doesn't work in multiplayer because of an "error".
#2) That Crytek gives NO MEANINGFUL ERROR MESSAGE DETAILING WHAT IS WRONG.

If you at least said something USEFUL in your ERROR MESSAGES, maybe the community could help you figure out what is wrong.

Put some €"%&#!! ERROR MESSAGE LABELS in your code (what is this 1970, for goodness' sake?). Instead of every error saying "Network Error. Quit now." which is akin to saying "You're screwed, nothing you can do to play because we said so", tell us "Pinging GameSpy authentication server on port XYZ timed out." or something that we can actually work with to track down what is wrong. Grrrr...

We *PAID* for Crysis 2, remember? And it doesn't work as advertised.

Hello, this is my first post
and...
I quote everything !!!

Very same issue here. This is extremely ANNOYING.
EA, Crytek, anyone out there PLEASE FIX!

It looks as though I am about to play a game, but the "Connecting to Server..." screen stays up. After a while it finally tells me "Connection to your multiplayer session has been lost. Please check network connectivity. Returning to the Main Menu." and it logs me out of my net. I was in a Ventrilo server and I got disconnected. This happened each time I would try to join a crysis server. Would any of this happen to do with my NAT Type being Moderate? If so any known fixes? I get disconnected each time I try to join a game. Sometimes it tells me "Cannot connect to host"

Well now it tells me "Invalid Parameter when I try to join a match. . . so I can't see the server list.

Please help.

I'm having the exact same problem, whenever i join a game i get it, haven't played a single mp match yet and my network is fine, never happened for me on any other game.

The netcode is broken just like in Call of Duty Black Ops, BFBC2... And is not compatible with older routers. You need to either open up the game ports, enable DMZ or connect directly to your modem.

Now I get this message about every five minutes. It's making it impossible to play multiplayer.

I use DMZ, and i get this too, every 5 minutes, if i succeed to join a game, i'll be disconnected before even killing someone.
This is so stupid because it was OK in the demo. Someone just broke something.

You got a lot to do Crytek, and you got to do it fast, you sold lots of copies to players who can't play... You know what it means.

I have a serious problem, I can't play anymore on multiplayer! Yesterday I was playing but when I decide to leave the session the game crashed so I had to close it trought task manager. Now when I try to re-enter the game it make the initial log in correctly, it steps into the server list, but when I try to connect to a server the game says tha the connection to the server is lost and take me back to the multiplayer main page. I've already tried to reinstall the game but the problem is still there...Any suggestion?

this is cryteks way of telling you they think you cheated, I will be honest , I modified some files to get rank 50 in 10 minutes yesterday, and it worked, shame on me, and I am having the same issue today, tried 30 + servers , same thing connection to session has been lost. it is not my pc , I am A+ certified tech, trust me, I think they are watching stats now. thats what I get .... lesson learned

this is cryteks way of telling you they think you cheated, I will be honest , yesterday I modified some files to get rank 50 in 10 minutes , and it worked, shame on me, and I am having the same issue today, tried 30 + servers , same thing connection to session has been lost. it is not my pc , I am A+ certified tech, trust me, I think they are watching stats now. thats what I get .... lesson learned

YES

It's about time.

this is cryteks way of telling you they think you cheated, I will be honest , I modified some files to get rank 50 in 10 minutes yesterday, and it worked, shame on me, and I am having the same issue today, tried 30 + servers , same thing connection to session has been lost. it is not my pc , I am A+ certified tech, trust me, I think they are watching stats now. thats what I get .... lesson learned

I dont think you can consider that a cheat, its crytek fault if they protect the file in the game.
For me cheats its aimbot, wallhack etc
You can be level 50 , 20 it doesnt matter as long you dont hack.

YES