Importing 12da Files into Civil 3D

If you are having issues importing 12da files into Civil 3D using the 12d extension, it may be an issue of how the file is encoded in 12d Model.  Read the Autodesk discussion thread below for a solution:

http://forums.autodesk.com/t5/AutoCAD-Civil-3D-General/A-note-for-People-Importing-12DA-files/m-p/4470095/highlight/true#M218012

Simply resaving the file with a different encoder will fix the problem.