Kaltura_Client_Exception thrown

Invalid KS "YzFlY2VlODQxM2JmZTI2OTZlYjBhNjc3OTI4MGQ3YTBlNDIxM2VhNnwxMDE7OzE0ODc4NDg0MTk7MjsxNDg3NzYyMDE5LjA0MTQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"