This is my first time running IW5M and I have this problem.

 

When I try to start the game I receive this error messagge

 

"Error during initialization:

Steam must be running for initial authentication to succeed. Please start Steam and restart the game to continue."

 

What should I do?

 

Thanks in advance

Download Steam and start it. Then run LaunchIW5M.exe and follow the instructions given..

Thank you very much. It's working but now I have another problem

 

patch_mp.ff is diferent from the server

 

What's the problem?

Thank you very much. It's working but now I have another problem

 

patch_mp.ff is diferent from the server

 

What's the problem?

Are you running the english version of the game?

if yes, just delete caches.xml and start the game or either try joining another server.