Thanks for providing this information Rene. I will mention it to the Office Support Tier 2 call that I am expecting this morning. Reason is, I too am having this same issue. My client has authorized me as a contributor ("can edit") on their Sharepoint
drive. When I click on a file that I uploaded to their directory, I can view it in the browser and even edit in Word Online.
However, when I click "Edit in Word", Word 2016 opens, asks me to sign into my Microsoft account, and then reports that it cannot, for the same error that you posted.
I opened a ticket yesterday with Microsoft and the agent escalated to Tier 2. Here is why....
I can download the file from my client's SharePoint directory and open the file locally, no problem. I then made a small change (renamed the file), and uploaded that back to the SP directory. Still cannot Edit in Word.
So, in a bizarre test, I deleted my Word 2016 and reactivated my older Word 2011. The Edit in Word from the SharePoint directory worked perfectly.
Like you, everything in my own OneDrive directory works fine with Word 2016. It seems that there is a break in authentication with Word 2016 when it asks to login to someone else's SharePoint directory.
I cannot really pin point this to a specific moment, but I can say that I upgraded my Mac to High Sierra. This prompted me to use Word 2016, because I read that Office 2011 support stopped in High Sierra. Guess not.
Stay tuned.....