Describes the cause and action for error messages.
2016 missing add-in tab
How to Fix the Disappearing Add in Ribbon Menu Bar in Excel ...
No Add-In Tab Though Add-In is Loaded and Working - Stack Overflow
Excel Add-In Not Showing in Ribbon
Excel Add In's Custom Ribbon Tab Will Not Display
Add-in Menu has Disappeared from the Ribbon Bar ? NEXT Analytics
Add or remove add-ins in Excel - Office Support
Excel Add-in Ribbon Disappears After Installation - Excel Campus
How to fix missing add-in in Outlook 2019, 2016, 2013 or 2010 - TechHit