Kaltura_Client_Exception thrown

Invalid KS "MzRiMGI0OTJkZjA5YmNkOTc0NmUyYTIxOGMzMWM1NWE1NWZkNzE0OHwxMDE7OzE0OTU5NDc4MzU7MjsxNDk1ODYxNDM1LjI3ODc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"