Policy
Disable all application add-ins
This policy setting disables all add-ins for the specified Office 2016 applications. If you enable this policy setting, all add-ins for the specified Office 2016 applications are disabled. If you disable or do not configure this policy setting, all add-ins for the specified Office 2016 applications are allowed to run without notifying the users, except if application add-ins are required to be signed by Trusted Publishers.
9eb4d0253181 L_Disableallapplicationextensions Registry
Copy registry mappings
HKCU\software\policies\microsoft\office\16.0\word\security\disablealladdins (enabled) = 1
HKCU\software\policies\microsoft\office\16.0\word\security\disablealladdins (disabled) = 0 Policy notes
This policy setting disables all add-ins for the specified Office 2016 applications. If you enable this policy setting, all add-ins for the specified Office 2016 applications are disabled. If you disable or do not configure this policy setting, all add-ins for the specified Office 2016 applications are allowed to run without notifying the users, except if application add-ins are required to be signed by Trusted Publishers.