[Trigger] Weirdest MUI/GUI Glitch

[RiotZ]

• Casts Build Menu Chaos
  • Events
    • Unit - A unit Begins casting an ability
  • Conditions
    • (Ability being cast) Equal to Build Menu (Chaos)
  • Actions
    • Set ResetAbility[(Player number of (Owner of (Triggering unit)))] = Build Menu (Chaos)
    • Set HQ[(Player number of (Owner of (Triggering unit)))] = (Triggering unit)
    • Set TempPoint = (Position of (Triggering unit))
    • Unit - Create 1 Builder (Chaos) for (Owner of (Triggering unit)) at TempPoint facing 270.00 degrees
    • Set BuilderUnit[(Player number of (Owner of (Triggering unit)))] = (Last created unit)
    • Selection - Select (Last created unit) for (Owner of (Triggering unit))
    • Unit - Order (Last created unit) to Undead Build

Every time this trigger runs, in a game of 2+ people, the other players' player cards disappear, i.e. whatever is selected, all buttons on the card disappear.

So wtf is going on here? Any ideas?

This looks 100% MUI to me.