loosing Teams meeting add-in in Outlook

I have a few users who are losing the Teams meeting add-in in Outlook. It is not disabled, its inactive. 
when you "GO" to the add-ins, its unchecked, but checking and restarting the app has no effect. 
Consequently, I found that the path to the DLL no longer exists. the \64 folder with the DLL is gone.

there is a new folder but when I tried to delete the original add-in to then add the new one, I receive an error message that new path was "not a valid office add-in" even though the same DLL file resides there. 

NEW

C:\Users\sample user\AppData\Local\Microsoft\TeamsMeetingAddin\1.0.24151.2\x64

OLD

C:\Users\sample user\AppData\Local\Microsoft\TeamsMeetingAdd-in\1.24.13005\x64