When using a selector with name=, if there is a mob with a custom name or username with a space or symbol in it, the player/mob is not able to be found by the selector.
Test:
1.Summon entity with CustomName with a space/symbol in it.
/summon Pig ~ ~ ~ {CustomName:/,CustomNameVisible:1}
2.Use a selector on entity.
/tp @e[name=/] ~ ~5 ~
3.Errors:
The entity UUID provided is in an invalid format.
Duplicate of MC-56246
Please don't try to duplicate your own tickets.