Ive gotten this error on some pieces of code, the code works whenever it isn't being updated

[live][3/10/2021 11:04:36 AM] Runtime error: [error] Expected an index    called from obj_moving_platform:Other_11[L2,c20]

It might have something to do with me using the user events rather than step.

This is the code that triggers the error

if live_call() return live_result;

if (instance_exists(creator))

{

x=creator.x+xOff*xsMult;

y=creator.y+yOff;

var xdif=x-xprevious;

with par_alive

if (noOneWayTime<=0)

{

if (id!=other.creator && y<other.bbox_top)

{

if (place_meeting(x,y+12,other)) 

{

if (!place_meeting(x+xdif,y,par_unpassable)) x+=xdif;

if (vspd>=0) 

{

vspd=0;

var spr_yoff=sprite_get_yoffset(mask_index);

y=other.bbox_top-spr_yoff;

}

}

}

}

}

else instance_destroy();