I'm not sure it is the same. Sprites are things like peeps, litter, and coaster cars. The limit is around 10000, but I don't think you usually get an error for it - it just stops spawning new ones. It looks like you recieved that error message when you selected that object, which means it isn't the object limit and probably isn't the sprite limit either. Given that the error originates from gfx_object_allocate_images, it looks there's a limit on how many images you can have loaded at once.