I'm updated on everything, how can I fix this? I was able to play before.

I was able to play before.

Restart your computer and maybe your router aswell and then try again.

If it doesn't fix it, then maybe some anti-virus update might be messing with the game.

I was able to play before.

Restart your computer and maybe your router aswell and then try again.

If it doesn't fix it, then maybe some anti-virus update might be messing with the game.

 

Restarted both, disabled AV, still nothing. Should I try to reinstall?

If you have a folder called raw, delete it.

I have almost the same problem,when I enter in some servers with maps such as "Crash" and others the game crashes and there is the message iw4m.dat has stopped working.. and when I play i any one server and then leave it the error is the same: iw4m.dat has stopped working...can anyone help?

Try deleting the "m2demo" folder from both:

 

C:\Users\USERNAME\AppData\Local\IW4M

and

 

C:\Program Files (x86)\Act*******\Mod*** ******* 2

(or wherever your game was installed)

 

and run the game in Windows XP SP3 compatibility mode.

It's because you guys don't have the DLC maps. Derp.

Google AlterIWNet DLC repository and it shall help you.

 

DLC map .ffs go in \zone\dlc\