Kaltura_Client_Exception thrown

Invalid KS "MDZkMzIxZGVmZGY2MDQzYTQ5ZmU1YjU4YTY0MzU2MWUwZmI2OTI2NnwxMDE7OzE0OTgyMjEwMjg7MjsxNDk4MTM0NjI4LjQ4MjU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"