I received a drawing that contains a layer in the manager box. But when I attempted to Quick Select that layer, the result returns as "0" and this same layer cannot be deleted, since the message tells me that layers with objects cannot be deleted. I thawed all layers and still get "0" and the layer won't delete. This should mean that the layer is hidden inside a block. This drawing has several hundreds of blocks! Is there an application within AutoCAD that will reveal to me which block that layer is in?