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 : w=600&h=500&zc=3&src=http://www.demirtasoto.com/uploads/jantlar/SH/SH%20724%20SM.JPG
TimThumb version : 2.8.10