MicroStation V8i (SS4) - Autocad 2018 Interoperability Issues?

We have recently had clients and partners begin using AutoCad 2018 to produce their drawings.  I am having issues with opening/referencing these files through MicroStation.  I updated my AutoCad to 2018 and I am able to open the files with that, but with MS I get an "unrecognized file format" error when attempting to open, and nothing happens when I attempt to attach the files saved with AutoCad 2018.  Is there something either myself, or IT, can do to get these files working properly through MicroStation once again?

Thanks, Sean