Can someone tell me what's going on with the attached DGN file?
There's a single line-string element. If I pop the Properties dialog it tells me that it's on Level (none)...
If I look at the Level Display dialog I can see level Structure. I can turn the display of that line-string off and on using that dialog. No DGNLib is attached.
StructureLevel.dgn
It may be relevant that the DGN file was converted from a DXF file.