Backwards saving a drawing from 2018

[Damian_E]

Is there an easy way to save a acad2018 created drawing in acad2016, after making changes?

All I get is a notification that one or more objects can be saved in 2013 format (our base format for saving files) no mention of which objects are incompatible, Purge & Audit have no affect on the drawing.

[hyunhokim]

In the DWG Trueviewer, You can use 2018foramt DWG to free.
It can convert DWG format any type.

[Damian_E]

The file was saved in the acad2013 format from Acad2018

[rkmcswain]

Are you using vanilla AutoCAD or a vertical (such as Civil 3D)?

With vanilla AutoCAD, SaveAs should do it.
If the drawing contains elements from a vertical app, especially C3D, then no you can't do this without stripping out those AEC objects.

Test it by starting a new, no-template drawing in 2018, and saving in 2013 format. Does it work?