Outlook 2016 Add-In requires elevation to work

[Stripes]

I built a vsto outlook add-in with c#. The add-in works fine, the problem comes in where i need to run outlook as administrator for it to work. The basics behind it is the add-in button is always disabled, until an email is selected in inbox,drafts, etc. Once an email is selected the button becomes enabled, but this only happens if i run outlook as administrator. Can anyone tell me why this is so, as our client do not wish to run anything as administrator, they have lots of security policies etc, which i cannot work around, i would greatly appreciate any help. PS. The deployment is done using wix, unsure if this makes a difference, it has registry entries.