GUI Loading near entity with specific conditions [SOLVED]

I'm trying to load the nearest entity in a gui that has a specific nbt set to true and that its UUID == UUID stored in a player variable. I don't really get what i'm doing wrong... sometimes it works sometimes it doesn't. Here's the procedure image:

The procedure is (obviously) in the model thing in the GUI

[SOLVED]

just do 

for each entity as entity iterator in a ... cube

     if get entity iterator UUID == StringVariableWithSavedUUID

       set LocalEntityVariableName to entity iterator

return entity : entity LocalEntityVariableName

This SHOULD work since i found the solution myself... if it's buggy or it works like the procedure in the image i'll try to find another solution and update the status of this project to not solved.