I have the same issue, just started a few days ago, as others have described:
- Receive a "Not Implemented" error when attempting to open an Office file
- Right clicking and selecting "Open with" the proper Office application for the file type and the file will open
- Opening Word (or the appropriate Office app) and select the file and the file will open
- Non-Office files (.pdf, .wav, .jpg) open with a double-click fine, no problem
- Rebooting fixes the issue, but only temporarily
I have Office 2016 on a Windows 10 machine. The only thing I have tried is the Office "repair" function and I noticed no change.
Since several others have reported exactly the same issue, it must be an Office or Windows change that is causing the issue, not something I've done. (I do not have TeamViewer.)
I'll keep monitoring for a fix!