Cryptomator won't accept Google docs

[infeo]

This is not an error specific to Cryptomator, see

Google File Stream Cannot Move Certain Files Around - SOLVED - Wisevu

To answer your other questions:

@LloydG

is there really a way to move a file into a vault on a Google Drive without using Google Drive File Stream in a Windows environment?

Maybe, you should try as suggested in the above article Googles Backup & Sync. In contrast to Google File Stream it holds always a local copy of your files.

@LloydG

When you use the term “local” are you referring to a gDoc that is in the Google Drive and somehow get it into the vault from the Google Drive web interface?

Local means that the gdoc file is stored on your harddrive outside of Google drive. So no. There is also no way to access your vault content from the web interface.