Issue:
The Vault Pro 2020 Add-in for Microsoft Office 365 apps for Excel and Word are being disabled as they load on a Windows 10 version 1909 workstation. Before version 1909 the add-ins launched normally. Also, the Outlook add-in works normally with version 1909.
Further, Excel cannot be closed after checking in a file into vault, after the add-in has been reloaded.
Causes:
This was tested on a domain that loaded Microsoft OneDrive and SharePoint as well as Microsoft Azure Information Protection. The Excel 2016 was running from Office 365.
Solution:
What was found to interfere with the Vault add-in was a Microsoft application called "Microsoft Azure Information Protection" inside Excel's Options.
Microsoft Excel Options (shown on a workstation in the Netherlands)
The confirmed solution was to uninstall "Microsoft Azure Information Protection" that appears in the Program and Features like this:
Once uninstalled, then Excel and Word were able to retain the Autodesk Vault Addin for Office 2016 and also check out, check in and close Excel normally.