I'm doing some support for a PM in one of our other offices and for her CAD tech there. The problem is that I'm using C3d 2018, while they have not upgraded since the 2015 version. I've worked out their plan and profile drawings, but if I send them my DWG (2018) they will not be able to view them (in 2015). As I understand, older versions of C3d won't read newer drawing file. What's the best way that I (from 2018) can send them something they can use (in 2015)? I don't want to convert my drawing to generic ACAD; I don't like the outcome.