Okay, I have had all kinds of problems lately, totally frustrated.
Civil 3D, Version G.204.0.0 SP2
Last night I had my grading drawing and it had all the feature lines, grading objects, etc in it. This morning, I went to open the drawing and the surface showed up in the preview, then still showed as it was opening, then it vanished once the open was finished. The surface shows the definitions of the feature lines in it but ALL the feature lines have vanished out of the drawing.
Yesterday I started getting this message *Warning* Multiply owned object, handle "99E6" and I used these to fix it.
(entget (handent "99E6")) will tell you what that object is.
(entdel (handent "99E6")) will delete it
Then when I got in this morning I have no feature lines... Think these are related? Help?
If recover doesn't fix the file then export the surface to xml. Import the surface into a new dwg and make sure the 'Create Source Data in Drawing' option is turned on for the xml import. You may get the feature lines back as 3dpolys.
Yeah not an ideal solution but it's the only one I know. On a side note I would rebuild the corrupt file.