For On-premise environment high-trust app -
We are creating a remote event receiver and handling the "App Installed" and "App uninstalling" events. When we try to install the app it fails with the error
The HTTP request is unauthorized with client authentication scheme 'Anonymous'. The authentication header received from the server was 'Negotiate,NTLM'.
This has been posted in a couple of forums and there are only a handful of blogs that explain- IIS website that hosts the remote event receiver web service should have "Anonymous authentication" enabled, atleast the service should be if not the entire website.
But I could not find a substantial explanation why this is required. Since SharePoint calls the web service, it needs anonymous access enabled ? And is this a necessary setting to make the remote event receivers work ?