It turns out that a lot of events don't agree too well with public bricks.
Are you using a default minigame created by the gamemode?You'll have to attribute bricks to your name otherwise.
function MiniGameSO::clearPlayerBricks(%this){ if(($DefaultMiniGame != %this && !%this.isDefaultMinigame) || !isObject(%this)) return; //don't let random players troll with this. only trigger the event if it was activated in the default minigame %count = mainBrickGroup.getCount(); for(%x=0;%x<%count;%x++) { %bg = mainBrickGroup.getObject(%x); if(%bg == Brickgroup_888888.getID()) continue; %bg.chainDeleteAll(); }}
Try surrounding the build with the slayer boundary bricks.