Can't select surfaces or feature line grips

[Anonymous]

I have a drawing that suddenly I can't select the surfaces for editing or select the feature line grips.  I can select the feature lines, and the grips are shown, but can't select them.  The surface is set to display points and triangles, but can't select the surface.  Both in-drawing and data shortcut surfaces are affected.  No locked layers, no locked surfaces.  Have recovered, audited, wblocked it out - no luck.  Only in this drawing - others behave normally.  Civil 3D 2016 SP3, W10Pro, I7-7700K, 32GB RAM.  

Thanks, Charles

[CivilFlow]

Hi- Open a fresh session of C3D and type RECOVER in command line and find the problem dwg file. See if the RECOVER command will fix any errors. I hope this helps.

[Anonymous]

I'm sure you've moved on, but I just had this happen today, so I'm sharing for future troubleshooters.  After a little investigation, the culprit was a skewed view.  Going to the view cube and resetting the view using the Top option corrected the problem.  Hope this helps.