I currently use 2013 Carlson Survey with Intellicad. When I receive CAD files from engineers using newer Civil 3D, I have trouble with certain objects and line work. What's the best/cheapest software to use to convert their file to something I can use?
Ask them to export the file to an appropriate format that you can use. That would be the cheapest option.
I think starting with C3D2014 the files will be backwards compatible. Until them no matter how you convert or "save down" you are going to have trouble using certain proxy items including survey points and some linetypes.
Like someone already said you will have to have the files saved back or exported to your version. However, this will not allow any true functionality and is really only good for viewing things. It's really a pain in the you-know-what, which is why we specify in our contracts that we will only supply our usable data in Civil3d(201?_) and that we will no be responsible for the integrity of any data that needs converted back to an older version.
Have you installed the "object enablers" yet?
I have not installed enablers yet. How do I go about that process?
Thanks
Keep in mind, doing a "save as" and doing an "export" are two entirely different commands. You ALWAYS want to use the export command to use Civil 3d drawings in earlier versions of ACAD.