/spawnpoint command and piston bug

I'm Korean. so my grammer isn't correct.

What actually happened was...:

• Piston Maked!

-spawnpoint makes UUID code. and can't run
Console Command : spawnpoint @a[team=zombie_zombie] 8 27 73
Privous Output : [22:17:49] 'e7df8746-d87b-45c8-9b62-2c6d2c34886c' is not a valid number