Office 2016 is a great improvement to Microsoft’s flagship suite of applications, but as businesses update to this via Office 365 or purchasing upgrades for their business people have found compatibility issues.
The issue is actually to do with having other products of the Office suite installed on the machine which are from a different era. Prior to the latest version you could have the main office suite of one version like 2003 with additional Office applications like Visio or Project of 2007.
Microsoft with 2016 have made the choice to not support running older versions of applications with any 2016 product. This especially causes people who are upgrading to Office 365 as they get forced to upgrade as part of the license you receive from Microsoft.
If you are looking at going at migrating to Office 365 or just looking to perform a basic upgrade for only the standard Office applications it might be worth contacting our support team for more information, or a plan to implement the new versions safely before spending on these solutions.