There are issues after the latest patch. Again. You're maybe a player who is affected by this issue, sadly. Ich hope for a fast fix.

got the same issue. tried everything but nothing worked. So we must wait.

Coop has always been a little flakey with this game. If you're trying to play with someone on steam, try joining with both the friends list and using a code that would normally be intended for cross platform.

Is anyone here able to join friends? I just spent the last two hours troubleshooting and my friend is not able to join my game and vice versa. We (unfortunately) both have the EGS version but I wonder if it's the same with the Steam version. I am able to join random/public games, just we can't join each other.

I also have the Epic version. I can coop with friends on Epic and crossplay with people on steam. So it's not a problem affecting everyone.

Thanks Bubba. If you (or anybody else with the EGS version) has a few minutes to help me test out the joining friend functionality that would be great. Add me on Steam and I'll send you my EGS gamertag. TIA!

We also have problems with Steam+Steam accounts with my friend. We have been trying everything and the end result is the same. Losing our nerves cause we just want to co op. WTF did we pay for if we are cracking some codes over here for five hours and still not able to play. CMON devs. You ♥♥♥♥♥♥ up the first one already.........

I got the Steam version - what we've found out with a bunch of testing is as follows:
~ Disable the cross play crap in settings
~ Have your hoster start their game in PUBLIC mode with however many game slots you need for your friends
~ Have the hoster invite each person 1 at a time
Note: If you have a 4 slot game and only have 2 people in there then you might get randoms joining.

Basically - Devs need to fix this co-op. If it's provided as part of the game then it needs to be working. Simples.

Delete all the blocked steam players list and then the file user_social_data.cfg. I know its not a good workaround but it works!