try "Hide (Leaderboard[Integer A])" before you do the show/getlocalplayer part
Hmm... I can see your logic and I would have thought it would work, but now NO leaderboard shows up for player 1 or 2... (I haven't tested other players but I assume it's the same).
Here's the trigger:
Make Multiboards
Events
Conditions
Actions
Trigger - Turn off (This trigger)
For each (Integer A) from 1 to 12, do (Actions)
Loop - Actions
Multiboard - Create a multiboard with 1 columns and 4 rows, titled Damage
Multiboard - Set the text for (Last created multiboard) item in column 1, row 1 to Lasers
Multiboard - Set the color for (Last created multiboard) item in column 1, row 1 to (20.00%, 80.00%, 20.00%) with 0.00% transparency
Multiboard - Set the text for (Last created multiboard) item in column 1, row 2 to Missiles
Multiboard - Set the color for (Last created multiboard) item in column 1, row 2 to (20.00%, 80.00%, 20.00%) with 0.00% transparency
Multiboard - Set the text for (Last created multiboard) item in column 1, row 3 to Engines
Multiboard - Set the color for (Last created multiboard) item in column 1, row 3 to (20.00%, 80.00%, 20.00%) with 0.00% transparency
Multiboard - Set the text for (Last created multiboard) item in column 1, row 4 to (String((Integer A)))
Multiboard - Set the color for (Last created multiboard) item in column 1, row 4 to (20.00%, 80.00%, 20.00%) with 0.00% transparency
Set Leaderboard[(Integer A)] = (Last created multiboard)
Multiboard - Hide Leaderboard[(Integer A)]
Custom script: if (GetLocalPlayer() ==Player(bj_forLoopAIndex-1)) then
Multiboard - Show Leaderboard[(Integer A)]
Custom script: endif