Posted by dellus on Feb 23, 2021; 11:02pm
URL: https://forum.librecad.org/Remove-the-empty-layers-tp5716976p5720263.html

Hey, that's a very good trick!
But keep in mind that in LibreCAD V2.1.3 you will lose the hatches (bug, solved in 2.2.0). Also you will have to take care that the new empty drawing has the same settings in Current Drawing Preferences.
So in further development of your trick, I had the thought, why not re-import to the same, but cleaned up drawing?
Instead of Copy, use Cut. Then, if you are lucky to have V 2.2.0 rc, you can delete all the layers, except 0, in one go. And then Paste back the contents including the used layers only.