If you have already tried the solution indicated in this article and the Outlook add-in is still not loading when Outlook is opened, then it may be due to a registry setting which determines how the add-in is loaded in Outlook.
To restore the default behavior of loading at startup the registry value needs to be changed to a value of "3".
Using Registry Editor incorrectly can cause serious system-wide issues that may require you to re-install Windows to fix them.
So, before making any changes in the Windows Registry, we strongly recommend that you make a backup of the registry first and contact your internal IT staff for assistance to perform these changes.
For more information about how to back up and restore the registry in Windows, please refer to this Microsoft article.
The instructions below explain how to adjust this registry setting (you need to have Administrator privileges on your machine to do so):
- Close Outlook.
- Open your Windows registry. To do so, press the Windows key on your keyboard simultaneously with the R key to bring up the "Run" box then type in Regedit and press Enter.
- In the Windows Registry Editor, navigate to the following registry entries: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\Outlook\Addins\InovaPushAddIn
- If the LoadBehavior is anything other than "3" then double-click the registry key to edit it.
- Change the Load Behavior to "3". Close the registry editor.
- Re-open the registry editor to ensure the LoadBehavior is still set to "3".
- Open Outlook. The add-in should now load automatically at startup.
If you need detailed information about the LoadBehavior values, please read this Microsoft article.