Comment 3 for bug 1626501

Try to work around the problem setting a number of headers in the XMLHttpRequest for example:

        xhr.setRequestHeader("User-Agent", "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:49.0) Gecko/20100101 Firefox/49.0");
        xhr.setRequestHeader("Accept", "application/rss+xml, text/xml;q=0.5, */*;q=0.1");
        xhr.setRequestHeader("Accept-Language", "de-DE,en;q=0.5");
        xhr.setRequestHeader("Accept-Encoding", "gzip, deflate, br");

But no luck still getting a 406.

Conversely use a heap of empty headers with wget still results in a response from this server: For example:
 wget --header='User-Agent: ' --header='Accept: ' --header='Accept-Language: en' --header='Accept-Encoding: ' --save-headers https://linuxgamecast.com/feed/lwdwmp3/

All very strange!