@The Aaron, I know. I saw the same thing. Don't know why prev has to be there as it isn't being referenced. However, I received the same ID not found error. I traced it back to the on change events for handleGraphicMovement, I commented out handleGraphicMovement onChange. It worked. I then commented back in those on change events, restored original code for that function and it worked. Now it could be FIRST time in, it fails, By commenting out those on change events, everything got set properly and the code change really isn't needed. Not entirely sure. And since I did reset that function (handleGraphicMovement) back to original code (with prev), I haven't been able to recreate the ID error.