Coop-Mode not working ! (Win 10)

Game mode: Co-op
Type of issue: Bug not connecting
Server type: PvE-Conflict
Region: Germany
Mods?: No
Edition: Steam


Bug Description:

Can´t join a coop-game, neither invite someone to my coop-game.
“Could not connect to the server, the connection with the game organizer was lost” everytime, when I want to connect to someone, or someone gets this message, when trying to invite my coop-game.
No Problem on online Servers for me.

We both have WIN 10 - same compatibility-mode
no mods installed
firewall deactivated
clean reinstall
data checked for issues
restarted router
de-/activated steam-overlay in game
etc etc

My friend can join and invite one of his friends coop. But I can´t.

Is there anything I can still do, or just have to pray and wait for getting this issue fixed in future ?

(read all the threads about this problem, too, since it started and recurred for years)

Hello, thank you for reaching out.

Could you please send us your full hardware details?

Hallo Rodric,

i know this is no help for you, but i have exactly the same problem and can’t find a solution.

Everything worked on my old computer with win 7 and on the new computer with win 10 it just doesn’t work anymore.