[Help] Combining 2 Structures into a new one

[Zallo]

Currently I have this trigger:

I am trying to make it combine two of the same towers into a new tower. I click the button and nothing happens.

 

[Daffa]

Is there any unit in Uncommon Units region?
The casting unit reference is lost after you remove it. Save the owner and the point to a variable before you remove it.
Do nothing is not necessary, just leave the else part blank.

 

[Rahko]

I'm not entirely sure what your goal is, but here is that above trigger in working form: (I also fixed the leaks)

Spoiler

• Combine Units
  • Events
    • Unit - A unit Begins casting an ability
  • Conditions
    • (Ability being cast) Equal to Combine Units
  • Actions
    • Set TempGroup = (Units owned by (Triggering player) matching (((Unit-type of (Matching unit)) Equal to Barracks) and (((Matching unit) is alive) Equal to True)))
    • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
      • If - Conditions
        • (Number of units in TempGroup) Greater than or equal to 2
      • Then - Actions
        • Set TempPoint = [Whatever point you want]
        • Unit - Create 1 [Unit you want to create] for (Triggering player) at TempPoint facing Default building facing degrees
        • Custom script: call RemoveLocation(udg_TempPoint)
        • Unit - Remove (Triggering unit) from the game
      • Else - Actions
    • Custom script: call DestroyGroup(udg_TempGroup)

 

[Pyrogasm]

So just so you know... there are abilities to do this already in the game, you shouldn't need to use triggers. Check out the Mount Hippogryff (and I believe the other is called "pick up archer" or something) and "dismount" abilities the Night Elves have. They allow you to target another unit and then combine with it specifically. I believe there are also a set of abilities to do this (and splitting) from the Firelord's spawn fire elemental spell (they break into smaller versions when they die).