Layers cannot be deleted

[Wolfgang_Schau]

I copied an object from a different drawing. The system added some layers to my drawing which may have come with this object. 

After I deleted that object, because it was of no use, I wanted to delete the imported layers as well, but the system refuses to delete them because it may contain objects or XRef dependent layers. Since the object has been deleted, it must be something else. Meanwhile I have double the number of layers, messing up my drawing with lots of unnecessary layers. 

Is there a way to inspect a layer what's in there, or what references prevent it from being deleted? 

[pendean]

@Wolfgang_Schau PURGE command is not mentioned by you: try that first. It works for unused content. Look up how to use it in HELP in the program if you need a refresher.

If you did use it (again, you don't mention it)... When you cannot use LAYDEL on a layer, using LYMRG instead to merge what you don't want to Layer 0 (that's a zero) is the next best thing if you don't want to get into using WBLOCK to rebuild your DWG file, or if you are not up to purchasing a 3rd party tool like this that seems to be able to blow anything away https://www.manusoft.com/software/superpurge.html

[R_Tweed]

Nice.. Never thought of using lymrg to select a large number of layers by name.  The will be very helpful when "hidden styles" are imported that reference named layers  and or layered block definitions.

[David_W_Koch]

You deleted the placed block.  Did you purge the block definition?  If not, then those layers that came in are still referenced, by the block definition.  There could also be nested blocks, whose definitions would need to be purged after the parent block definition was purged.

[Wolfgang_Schau]

How can I delete the block definitions?

[David_W_Koch · Accepted solution]

@Wolfgang_Schau 

Use the PURGE command.