[MC-85905] Summoning Mobs with a dragon head

I am not sure if it's the dragon head or the off hand, but when I use this command, "/summon Zombie ~ ~1 ~ {ArmorItems:[{},{},{},

{id:skull,Damage:5,Count:1}

],HandItems:[

{id:iron_sword,Count:1}

]}" to give a zombie a dragon head and a sword in it's main, and off hand the game crashs.