This is due to the office outlook registry being corrupted where it will need to be recreated to resolve to do so:

**Be aware that this will somewhat recreate the user's outlook profile to an extent**

Make sure Outlook has been closed

  1. Open up Regedit (the user needs to put in their pw as this will not work otherwise)
  2. Go to the following location: \HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook and rename the Outlook entry to outlook.old

Also go to:

\HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook and rename the Outlook entry to outlook.old

Now open Outlook back up and the plugin should stay now. You may possibly have to refresh the integration by opening the related add in program after editing the registry(Newforma for example). -AC