OnMouseOver is used to detect if a mouse is over a collider or GUI element - but I didn’t see anywhere saying whether it’s called for CharacterControllers?
If no one has an answer I’ll test it soon and post my results.
A character controller is a collider.
As far as testing it you should have done that first.
I tested it quite a bit and OnMouseOver seems buggy, not detecting clicks on colliders as it picks and chooses when there are multiple colliders around - even when the other colliders aren’t close to the one im clicking on, so I switched to using Raycasts which works perfectly.