Background: Foxit add-in displays in the Microsoft outlook Add-ins menu, Foxit PDF add-in doesn't display on the top ribbon of the main outlook window.
Troubleshooting process:
1. Clean cache data in Registry Editor
Open Registry Editor > Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Resiliency, delete folder Resiliency
Navigate to Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Addins\OutlookAddin.OutlAddin, delete folder OutlookAddin.OutlAddin
2. Re-load Foxit Add-In again
