Configuration Error

Check the HTTP server's authentication settings.

The HTTP server did not provide the username in the HEADER header when it forwarded the request to Gerrit Code Review.

If the HTTP server is Apache HTTPd, check the proxy configuration includes an authorization directive with the proper location, ensuring it ends with '/':

<VirtualHost review.example.com:80>
    ServerName review.example.com

    ProxyRequests Off
    ProxyVia Off
    ProxyPreserveHost On

    <Proxy *>
          Order deny,allow
          Allow from all
    </Proxy>

    <Location /r/login/>
      AuthType Basic
      AuthName "Gerrit Code Review"
      Require valid-user
      ...
    </Location>

    AllowEncodedSlashes On
    ProxyPass /r/ http://.../r/ nodecode
</VirtualHost>