That event is nonsense: why would you want to do that every 5 seconds? That goes against correct usage of the 'Associate object' action: it should only be used in multiplayer events like when peers join, like the tutorials describe. I'm afraid I'm going to close this because the example given does not appear to be a valid use of the action so there's no need to fix anything with it.
Remember families and objects pick their instances separately; I also don't know why you are trying to pick an object by its UID from a family it's also in, when you could just reference the family instead.