R 6 SR12 (1/29/19) can't rename or delete layers

Per the subject I have a 3dm created from an imported DWG. I click new layer and get Layer1 but cannot rename it. MANY existing empty layers I want to delete. Not possible. none of them are locked.

Thoughts?

Robb

Just back at it and it works now. Troubling inconsistent behavior…

Hi Robb - just to make sure: are you importing or inserting as a linked block?

-Pascal

It was a DWG from another person that I opened. Not sure of the source software. It had 1 layout sheet. I had saved it previously to 3dm (not sure if done in v5 or v6) then opened the 3dm a couple of days later in v6 on my laptop to get to work on it. The problem occurred immediately as I tried to reorganize the layer structure. Multiple failed efforts, then i closed the file and posted here. When I reopened, everything worked as expected. Totally weird.