I am trying to delete layers from old drawings that appear to have nothing on them. But when trying to delete them( after I have exploded the relevant layers and still found nothing) it comes up with an error message and I am unable to delete in the layer manager - can anyone help with this?

Additionally, on another drawing I am trying to merge multiple layers to create a flat image to copy across to another tab, when cutting and pasting as a block together to the relevant new layer, all original layers (which I previously deleted) are pasted into my new drawing.

Any help appreciated! Really struggling!