Cannot play with friend - Unknow joinEvent (fixed)

[Drusk]

As title say, whenever i try to join or invite my friend we get an unknow join event error.
We have tried restarting game, steam, pc, verify game etc

I understand from various other posts that this issue has been around for ages and no apparent solution was found other than it starting to work again randomly

Is that our fate ?

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Update after more troubleshooting :

It works.
So.
The issue was, likely, that i had an old .module back up file in my game folder.
My guess is that the game loads any .module file regardless of their name, thus causing the malfunction.
I feel stupid but it works now.

Have fun people

[The Unknown Writer (Busy)]

huh