Summary, for end-users

If you use a Mac and ChemDraw, now is the time to learn the procedure to copy-and-paste ChemDraw elements for round-trip editing with MS Office 2016 documents. The changed occurred after Microsoft Office 2011 (Mac) and staying with that version of Office is not a viable long-term solution.

...

With the end of the support lifecycle for Office 2011 on 10/10/2017, it may no longer be possible to install Office 2011 on newer versions of macOS.  

Chemistry IT sharing information to the department:

• http://blogs.cornell.edu/chemit/2017/08/22/macs-office-and-chemdraw-issue/

Prior cautions information from Chemistry IT on this topic:

• http://it.chem.cornell.edu/2016/12/19/new-chemdraw-16-mac-roundtrip-editing/
   
• http://it.chem.cornell.edu/2015/10/30/chemit-flash-2015-10/

What you need to know: Mac's MS Office and ChemDraw

...