Game crashes when I summon zombie riding zombie

ALERT: IT SAYS THE EFFECTED VERSION IS 1.8, BUT IT IS 1.7.10. IT WOULDN'T LET ME TYPE THAT IN.

When I used this specific command on a command block

/summon Zombie ~ ~1 ~ {CustomName:"Dinnerbone",CustomNameVisible:1,Equipment:[{id:diamond_sword,Count:1,tag:{Unbreakable:1}},{},{},{},{}],DropChances:[2.0F,0.0F,0.0F,0.0F,0.0F],Attributes:[

{Name:generic.maxHealth,Base:1000}

,

{Name:generic.movementSpeed,Base:0.5}

,

{Name:generic.followRange,Base:1000}

],Riding:{id:"Zombie",Attributes:[

{Name:generic.maxHealth,Base:1000}

,

{Name:generic.followRange,Base:1000}

]}}

the game pretty much whacked out. The command block did not process the command, the game started lagging horribly. Then, I saved and quit. When I tried to open the same world, it simply kicked me back to the homescreen, then sending me to the crash screen. I tried to get in several times, but it crashed every single time.