A TimThumb error has occured

The following error(s) occured:

The remote file is not a valid image. Mimetype = ''/data_tmp/image_work/timthumbgudR3T

Query String : src=https://img.washingtonpost.com/news/to-your-health/wp-content/uploads/sites/26/2016/07/ca.jpg&w=60&h=60&src=https://img.washingtonpost.com/news/to-your-health/wp-content/uploads/sites/26/2016/07/ca.jpg&w=60&h=60
TimThumb version : 2.8.11