I have the same Problem like the guy 2 month ago,  when i want to join a multiplayer game the button is grey and if i go with the cursor on it the Massage Steam is not running comes in red, but steam is running and the Game overlay does not work (whats not important). I never had any problems with other games on steam.

I reinstalled the game, veryfied the data, reinstalled steam, launed as administrator, reinstalled my GPU drivers, the c++ 2010 environemts and used the win 7 compatible mode.

DxDiag.txt

i do not have the dignostic or output file, when are they created? 

And i do not know if its helpfull but at first i could creat no game until i startet everything as administrator. Strange was that i could start ES2 only through steam, if i used the .exe a black screen just popped up for a second. Now i use the .exe with compatible mode win 7 and i can start without steam. 

Thanks for your help

Sorry to hear that you're having issues.

What antivirus software are you using? Did you try disabling it for a test?

Do you have any other software running constantly in the background? (I had issues with Radeon ReLive, I think nVIDIA has something similar...)

Its strange, i do not know what i changed, i still cannot use the steam Overlay, but i can join games so thats enough...

Tanks so far