VSTO add-in not showing up in O365 Business RRS feed

  • Question

  • Hi,

    I have a VSTO excel add-in, this add-in works perfectly fine (many clients are already using it) with all versions of Office from 2010 to O365 Pro Plus.

    Recently we wanted to install this add-in, in a user machine having O365 Business, after installing Add-In it is not showing up in excel, we checked the list of active/inactive add-ins and it is not showing up there, we also checked the list of COM Add-Ins but it is missing there as well. So it seems the Office365 Business installation is not able to identify this Add-In.

    We tried to add the add-in from the COM-Add-In dialog, but it throws an exception saying that it is not valid COM object.

    All the necessary registries are properly created under  HKEY_CURRENT_USER\Software\Microsoft\Office\Excel\AddIns.

    One thing we noticed was that O365 is installed under InfusedApps\Packages\Microsoft.Office.Desktop.Excel_<build number>\Office16

    So i wanted to know what might be the probable cause that excel is not identifying my VSTO add-in? and what can be done to fix it.

    Appreciate all your help.


    Friday, September 6, 2019 8:04 AM