Unable to join server
Confirm the host is online in Steam, restart the room after changing privacy or password settings, have all players update the game, and test with a smaller lobby before inviting everyone.
Crash, black screen, or freeze
Verify game files in Steam, update GPU drivers, disable overlays one at a time, lower graphics settings, and relaunch Steam before rejoining the same room.
Controller support
Enable Steam Input for the game, test the controller on the main menu, and avoid switching devices after joining a room.
Steam Deck checks
Start with conservative graphics settings, confirm the lobby works before choosing a heavy Workshop map, and keep the device plugged in for longer party sessions.