Benson, I tried your suggestion. Still cannot edit it.
Here is the file with the one pasted line.
It says it is a 3d polygon, so i tried converting to lines but the line segments are 8" long and do not show the dashed characteristic I want. I then tried converting to polygon, selecting wireframe rendering and could then edit and it seems to show the desired class style dash line type.
I use Windows version 16.
Thanks for you help.