Thanks for the quick reply. I see where you're going, but I don't think that will work.
1) You can't promote a broken reference/data shortcut.
2) Even if I could promote it, I don't want to paste hard data into the profile sheet set as we are often changing design (i.e "pick up that storm line and put it over there, and I need a new profile right away")
I feel like I've tried everything, detaching and re-attaching the drawings, inserting into new drawings with the same name... nothing seems to work.
The error is "Broken AeccDb SurfaceTin Reference". Oddly, in the Civil 3D object model it doesn't mention a tin.
Any ideas? (Please don't reply with "upgrade")
Casey
Civil 3D 2006, SP2/HF2