Crash when opening world

I made a command: /replaceitem entity @s [type=zombie_pigman,r=100] slot.weapon.offhand 0 map 1 and then i changed the command block to repeat and always active and then i turned around opened a chest not noticing any lag and i crash if i log back on the world again I CRASH even if its done loading! Please Fix Bug and my game. That was my favorate world