Grant File Access: Word cannot open the document: user does not have access privileges

You'll most likely find that you must repeat this every month, when you install an update. Every time I've tested the updating process, the fonts get reinstalled in the package.

It's worth a try creating a new user account on your colleague's Mac, sign in to it and test Office. If it works, you know it's some degree of corruption in the old account's installation.

Unfortunately, Microsoft has never published really complete uninstall/reinstall directions for Office 2016 for Mac. I think it likely they don't know how.

After working with my client for over a year, I have finally got higher ups in Microsoft Mac Development to acknowledge this bug and they are currently working on it. At least in our instance, the issue stems from activating too many fonts with a 3rd party font manager like Suitcase of FontExplorerX. The amount of fonts is usually in the 3k range, which then causes Office 2016 to act all loopy and throw up random error messages.

If you aren't using a 3rd party font manager, then your issue could be different. For those that are using a 3rd party font manager, Microsoft Developers are working on this and they expect a fix in the next couple of releases. I'll keep this thread up to date as I find out more information.

I had this problem too and it comes back sometimes after an Office update, like the most recent 16.9.1.

What I do is clearing the MS-Office font caches with Cocktail and then restart my Mac immediately. Word then opens the documents without error.

Worked for me with 10.10 Yosemite and 10.11 El Cap / Mac Pro 2008. I'm using FontExplorer X Pro 6.

Hope it helps.