Contraptions and farms which use blocks in illegal positions (e.x. tnt duping) often break when the level.dat is forcefully changed. To reproduce this bug, one can:
1. create a new world
2. set up a TNT duper
3. save the world and quit to the title screen
4. edit one aspect of the level.dat file (e.x. time)
5. reopen the world
❌ the tnt duper has updated and stopped working
Invalid unless this can be reproduced without external tools