Office applications cannot open some files if the path is long or contains some special characters. It happens at least with Word, PowerPoint and Excel. I do not use the other Office applications.
Interestingly, such three applications behave in a different way in relation to such issue. It arises more with Excel and less with Word. Besides, they report the issue with a rather misleading message:
Sorry we couldn't find your file. Was it moved renamed or deleted?
I reported that before several times to no avail. Since the file is in the Mac disk, the Office applications should open it. Is there a way to prevent it? If not, it would be great if Microsoft could fix it.
Current system: Office 2019 (not 365) version 16.29.1 (19091700) for Mac on macOS 10.12.6 (16G2128) Sierra on iMac 27-inch Retina (mid 2017).