I went to sleep, paused my game, and quit for a few hours. When I came back on, I was trapped in a small stone room underground. I used the 'kill' command, spawned at one of my backup houses, and then went back to my regular house, which is underground with a lake. I crossed the lake, and where my underground room should have been, there's only a wall of stone. Can someone tell me what happened and how I can get my room back?