I have a "player" object and a platform it can stand on, and when it does, said platform falls downwards. In order to make the player stick to the falling ground as it falls, it has to instantly go at the same speed (be moved down the same amount of pixels each frame) as the platform. This is done by the platform reading the y coordinate of the player using "[player object name].y". This works fine, until the moving platform falls beneath a stationary one, and the player object stands still on the stationary platform. At this point, for an unknown reason, the moving platform becomes unable to read the y coordinate of the player, saying that it can't find an instance of it in the error that it raises: "Unable to find any instance for object index '3' name '[player object name]'". I think it goes without saying that there is only one instance of the player object in the room, and it definitely still exists when the error is raised. Why is this happening? Is it something to do with the index thing in the error message?