406 is the status returned when the HTTP request has "Accept" headers that are incompatible with what is being requested or what the server is set up to deliver.
406 is the server telling you "I have what you asked for, but you won't accept them".
"406 Not Acceptable" is an unusual status code - the most common are 200, 404, 500, 301. You only see a 406 when something is wrong with the server, usually something silly but hard to diagnose.
It is something server side (not script side) Talk to your host and see what they can do or go get another host
