AutoCAD 2018 and Revit Compatibility

For the first time in several years AutoCAD has a new DWG file format as seen in the AutoCAD 2018 Save As dialog below.

I suspect the new version of Revit (i.e. 2017 + 1) will be able to successfully read an AutoCAD 2018 file. Also, as one should expect, Revit 2017 cannot read an AutoCAD 2018 file given the new file format. However, the twist here is if you try to link an AutoCAD 2018 file into Revit 2017 you get a few familiar warnings (see next two images) and then nothing happens - no file linked and no specific error message about what happened.

If you are a Revit user and get a DWG file you cannot link into Revit 2017 or earlier it may be a 2018 file. It will have to be saved as a previous version in AutoCAD.

Speaking of compatibility... if a DWG is saved with AutoCAD Civil 3D 2017 it can be opened in AutoCAD 2016 (or AutoCAD Civil 3D 2016) but not saved. This "corrupt" file cannot easily be saved or exported to a workable format. The file is not really corrupt, but Civil 3D modified the base DWG file in such a way that it is not backwards compatible like a normal AutoCAD 2013 formatted file.