We are using iMacs, running Sierra. To try and solve the problem shown in the attachments we have now upgraded our computers to Microsoft Office 2016 and it has not solved our permissions problem. (I surely cannot be the only person on the planet who has this problem.)
I have attached before and after PDFs for you to look at.
The file in question is stored on our main administration computer. You can see from the “Before” shot that lots of users have permission to read and write.
We opened the file from one of our other computers, put a dot in a cell, saved it and closed it. Now look at the “After” shot.
I have checked for, downloaded and installed every available update for Sierra and there aren’t any for Office 2016.
Obviously, I am at my wits end. I have had so many technical people “in my computers” trying everything they can think of, but to me it seems like something that needs to be addressed by the team that developed Sierra. We should have stayed with Snow Leopard :-(