If, for some reason, you want to enable unstable objects, paste this at the bottom of mod.json: , "removeUnstable":{ "name": "Remove unstable blocks", "description": "Removes blocks that are likely to cause the game to crash. I do not reccomended turning this off", "type": "bool", "default": true } , enable the commented lines of code 42, and 52-54 in main.cpp, and comment out or remove line 43. This is nearly guarenteed to cause the game to crash when entering the level editor.