The current, public version of Papers does not support Microsoft Word 16.9.
We have gotten reports of this update causing crashes on machines running OS X 10.10.5. Please only do this if you're running OS X 10.11 or above.
To do this, please launch Papers and head into Preferences. Once there, you'll see an option near the bottom to be informed about pre-release and beta versions of Papers:
Once you do this, quit Papers, re-launch it and that update will be available to you.