Hi Maxim,

Unless my software is really out of whack, unfortunately the objects you are discussing are on the layer "rough openings", not "N Trellis". 

There is one odd thing that happened. I decided to delete all objects on "rough openings". I then was finally able to delete layer "N Trellis". 

The really odd thing is this. I reinstated layer "N Trellis". I then  reinserted the objects I had deleted on layer "rough openings".  I then was able to delete layer "N Trellis".  

Could this mean my software was mistakenly assigning objects to both layers "rough draft" and "N Trellis"?