When working with a DWG file that was created in AutoCAD Civil 3D, you've noticed that the file becomes excessively large when opened with F/X CAD or AutoCAD.
This issue may be occurring when the main drawing file, or even one of the attached Xrefs, was created in AutoCAD Civil 3D.
F/X CAD and regular AutoCAD are unable to read some objects that are created by AutoCAD Civil 3D. Autodesk offers what's known as the Object Enabler, which is a patch that allows these objects to be viewed in versions such as F/X CAD and AutoCAD.
Unfortunately, the Object Enabler can sometimes cause these files' sizes to balloon when they're opened.
We've seen the latest Autodesk Service Pack for Civil 3D resolve this issue.
Any Civil 3D users who regularly send you drawings will need to download and install the latest Service Pack for the year version of Civil 3D that is installed on their computers.
Once the latest Service Pack is installed on a Civil 3D workstation, the problematic file can simply be opened and saved on that workstation. Once saved in this way, the file can be opened in F/X CAD or AutoCAD without bloating in size.
Note that the Civil 3D user may also need to open and save any files that have been attached to the problematic file as Xrefs.
Note that if the file is opened on a Civil 3D workstation that does not have the latest Service Pack installed, the issue with increased file size will likely occur again if that file is opened in F/X CAD or AutoCAD.
Want more information on the Civil 3D Service Packs? See the official Autodesk document on the subject.