Trouble playing co-op through Steam's Join Game

[cim]

tldr: What ports (UDP/TCP/both) do Dead Rising 3's net code use on PC through Steam? Is there possible to join a specific player through the multi player matchmaking?

Hello! I've done a search on this issue on the discussion board and found little information.

When I launch the game from my saved state (story mode) and a friend tries to connect to the game through Steam's Join Game function he disconnects before he's in the game. He has managed to connect a few times before being dropped out after a time span of 5-10 minutes.

I've done some googling on port forwards, but only found results for the Xbox One version and Dead Rising 2. Being naive and slightly frustrated I forwarded those ports in my modem to no avail.

Co op seemingly works alright through the built in multi player matchmaking system, but this system serves no purpose when I want to play with people I actually have on my friend list. If you know of a way to join specified players through the matchmaking system do say.

[Re:Start-E.D.420]

The only thing I can say is follow the list of steps:

• Run Steam as Administrator
  
• Turn of Windows Firewall completely
  
• Delete everything in the Steam folder except for Steam.exe and steamapps folder, then run Steam (it will repair itself automatically)

Is your friend able to do coop? You shouldn't need to forward your ports, as I was able to do it just fine with my friend. If your friend can't join anybody's game, have him verify the files.

I'd also venture to say this is a Steam problem, not a problem with the game. So try googling the problem but this time about Steam

[cim]

My friend is able to co op through the matchmaking system, the same as I am. I'll try your steps, currently not running Steam as admin nor have I emptied the Steam config files, but Windows firewall is off.