The script freezes the game

I was making a block that will grow another block in any of the 6 random directions when bone meal'd.

But when i use bone meal on the block it jst freezes the whole game, by that i mean that every mob/action except placing and breaking blocks dont happen anymore. Like mobs dont walk or get damage, and when i throw out items they dont appear. Also i cant change gameModes or use any commands, nothing just happens.