For example, if I use the Storage Drawers mod to place a few blocks with inventory and then save and shoot them via Schematic, the server will kick you all the time in multiplayer and you can no longer access your world in singeplayer. If you try to join the world, the game crashes. In singleplayer it is also possible to destroy the whole world generator with a low probability. You can no longer make worlds and must either reinstall Minecraft or build in multiplayer.

Issue resolved by jaquadro/StorageDrawers#786

mod incompatability