Layers I can't delete in MDT 5

I have extra layers in my drawing. I wrote an autolisp program that changes all entities in a drawing to layer 0. I verified the program by checking the entities. There are xref'd blocks in the drawing. I changed entities in those drawings to layer 0. The xref'd blocks do not contain the layers I am trying to delete. Everything is on layer 0, BUT, I still have unused layers in the drawing I can't delete.



I can delete one of the layers if I delete the drawing views created from the model (which was not on layer 0 originally). This is not practical because I need to run this program on approximately 1000 drawings. Still, other unused layers remain. No, these are not layers created by Mechanical Desktop when views are created in paper space. These are layers created manually by an overzealous drafter.



Could there be something buried in the model at the sketch, extrusion or feature level that I haven't reached? If so, how do I access it?

Thanks,

Dan

 

Are the layers frozen in a viewport?

 

No they're not Frozen but when I erase the viewport the layer can be deleted. I guess the layers are somehow attached to the viewport.

Dan

 

We're trying to find a way to move the parts (about 1000) in Mechanical
Desktop assemblies to layer 0 so they will be the same for another lisp and
VBA I'm writing.

Dan

 

I hope I don't have to do it. I'm not sure I have to now. I'm writing a
VBA using about 6 frames with optionbuttons in them to collect options so to
turn off layers.

I'm having trouble getting more than one frame working. Can't use control
array's as in VB and trying to figure out how to procede.

Dan