Helping one of colleague from CWA team on the issue where browsing any static content[htm/jpg] is ending with blank white screen on the browser. That prompted me to look into IIS logs . Here we saw 500 0 1346. As the next troubleshooting step we configure FREB for the 500 error code.
Here we see :
ModuleName IIS Web Core Notification 2 HttpStatus 500 HttpReason Internal Server Error HttpSubStatus 0 ErrorCode 2147943746 ConfigExceptionInfo Notification AUTHENTICATE_REQUEST ErrorCode Either a required impersonation level was not provided, or the provided impersonation level is invalid. (0x80070542)
Authentication:: anonymous User from token:: NT AUTHORITY\IUSR
That means we are using Anonymous access and the credential token passed as NT AUTHORITY\IUSR
Resolution provided was to make sure
The IIS_IUSRS group should be in "Impersonate a client after authentication" in the local security policy.