Trigger Help - specific unit entering a region

I've been messing around with this map lately, and there are a few bugs innit:

This trigger dosnt seem to work at all.

EVENTS:
Unit - A unit enters "Region 1" <gen>

CONDITIONS:
(Owner of (Entering unit)) Equal to Player 5 (Yellow)
(Owner of (Entering unit)) Equal to Player 6 (Orange)
(Owner of (Entering unit)) Equal to Player 7 (Green)
(Owner of (Entering unit)) Equal to Player 8 (Pink)

ACTIONS: (Don't worry about these)
Quest - Display to ??? ???
Sound - Play ???
Trigger - Turn off (This trigger)

I want only the units who belong to player 5, 6, 7 and 8 to take effect on this trigger. But once I enter the region with one of the units belonging to these players, nothing happens. Why?

Any help would be greatly appriciated.

(I've also tried "(Owner of (Triggering Unit)) Equal to Player 5 (Yellow)", still no reaction)

that's wrong, the unit can't be owned by 4 players at the same time.

Only one of the events needs to fire to make a trigger run, but EVERY of the conditions should match to execute it, so you'd have to use the OR condition

This one if u want either of them to work:

Or - Any (Conditions) are true
Conditions

And this one if u want all them to be true:

And - All (Conditions) are true
Conditions