Error DECT no coincide

Hey there.I'm trying to run a multiplayer game which worked perfectly last week but happen to encounter an error when trying to launch a multiplayer game.Says "Error DECT no coincide".I have no clue what this is about and how to solve it (not a single topic about this on steam nor on google) so i'm here to get some help.The error always occurs when we are effectively launching a dungeon, and it doesnt depend on :- the one launching it (both tried)- being alone or not in the lobby- choosing another map (we were about to do 5-6, but we also both tried to launch 1-2 and didnt work either).We already both :- dc/rc from steam- verified the cache integrity of the gameDoes anyone know about this error and how to solve it ?Thanks.Screen : https://imgur.com/a/cjy4i