In a multiplayer game one player sees doors as solid concrete or wooden blocks and can't passIn a multiplayer game, one player sees doors as solid concrete or wooden blocks and can't open them or even pass through them if they are open. If one of the other players that sees and operates the doors properly destroys them and then the affected player picks it up, it shows as for in their inventory, but then as soon as they reposition them, they appear as solid blocks again. I attach two screenshots showing how the same object appears different to the two players.