A TimThumb error has occured

The following error(s) occured:

The remote file is not a valid image. Mimetype = 'text/html' File = /var/www/html/timthumb/cache/timthumblfvV0g

Query String : w=640&zc=1&a=c&src=http://campingsanteodoro.com/gestione/uploads/photo/36227_camping_la_cinta_bungalow3.jpg
TimThumb version : 2.8.13