Put the summary of the bug you're having here

What I expected to happen was...:
a redstone clock with a command block with /execute @p ~ ~ ~ execute @e[r=10,type=!Player] ~ ~ ~ playsound random.pop @p should make it so when i get near to an entity it rapidly plays a pop sound.

What actually happened was...:
it says it failed to run the command as me

Steps to Reproduce:
1. make a redstone clock with a command block
2. enter /execute @p ~ ~ ~ execute @e[r=10,type=!Player] ~ ~ ~ playsound random.pop @p
3. get near an entity or entities, and notice how there is no pop sound.
4. check command block for the error message.