A TimThumb error has occured

The following error(s) occured:

Could not create the index.html file - to fix this create an empty file named index.html file in the cache directory.
Could not create cache clean timestamp file.

Query String : src=http://www.cremona.hu/wp-content/uploads/2014/04/P1060273.jpg&q=85&w=200&h=200
TimThumb version : 2.8.11