The problem is: there is no way to retrieve the player who started the ability if the unit starting the ability is owned by a different player.
This is a problem that only exists for units like taverns who share ability control.
What you could do in this case is save the player of the unit that the tavern got selected through it's Select Unit ability in a temporary variable.
However, this will cause problems for whenever there are more players in game because whenever a new unit gets selected,
that unit will be the new temporary unit instead and therefore might make the ability work for the wrong player.
What you could also do is: create a dummy unit for each player.
Then whenever a unit is selected by the tavern and the player owning this unit is for example player 1 you could redirect them to the player specific dummy unit.
These dummy units are then owned by that player and thus allows you to have the triggering player and owner of triggering unit refference.
See what I want to say here? It's a lot of trouble for something that can be done with sold units instead...
Using sold units is not only easier but also faster, so do this instead if you want to keep it simple.
Also, a tip: don't use Do Nothing, it is a waste since a function is called that does.... nothing.
Each function that is called takes up a tiny little bit of your trigger's speed
I just gave you 2 options on how to do it, pick one.
