I play on a multiplayer server with my two roommates. A few times we have returned to the game with hours of our work suddenly not there (i.e. we dug tunnels to connect two caverns and upon logging back into the game, the tunnels were not there). Another time we built a large building - about five hours of game play - and upon returning to the game the next day, half of it was gone - and it isn't a rendering problem. The game is being hosted on a Macbook Pro through a LAN network, using Hamachi. Is there a command that brings back our work? What should we do to correct this issue?