Teleporting @p to @e

I was trying to make a teleporting snowball by doing

/execute @e[type=Snowball] ~ ~ ~ tp @p @e[type=Snowball] {InGround:1b} 

Then it says the UUID is in an invalid format like 100 times

I thought it would tp me to it when the snowball lands so i think you should test it and fix it next snapshot.

THANKS