Warning: Permission Denied, While clearing the cache When I clear the cache of the site, I get lot of warnings with 


  "Permission denied in drupal_unlink() (line 2199 of home/public_html/sitename/includes/file.inc)."


And I am unable to upload any default image to the site with the warning 


  "File Could not be uploaded"
Check your temp folder under "admin > config > media > file system": It should be writeable.