A TimThumb error has occured

The following error(s) occured:

Could not find the internal image you specified.

Query String : src=http://www.waarismijnknuffel.nl/media/catalog/product/cache/1/thumbnail/9df78eab33525d08d6e5fb8d27136e95/0/_/0_296e2468abf13c673a1b328362f6e0a0.jpg&h=500&w=500&zc=1
TimThumb version : 2.8.14