Developing an office 365, outlook add-in. Changed the add-in icon (Basically just replaced the old icons with new one. Icons have the same name.). Icon comes up fine on OWA but on Outlook 2016 add-in still, shows the old icon.
Troubleshooting steps till now :
- Uninstall reinstall add-in => no effect.
- Uninstall add-in, restart Outlook 2016, reinstall add-in => no effect.
- Reset customizations from 'Customize Ribbon' option inside 'Outlook Options' => no effect.
- Restarted server => no effect
validate-office-addin shows 'manifest.xml' as valid.
You need to delete the local cache. Delete the contents of %LOCALAPPDATA%\Microsoft\Office\16.0\Wef\
I resolved it by simply renaming the icon files and updating the manifest files accordingly.
来源：https://stackoverflow.com/questions/45332761/office-365-outlook-add-in-icon-does-not-update