Kaltura_Client_Exception thrown

Invalid KS "MzMxMTI2MWI1MDA2NzExNmY3YTQyYzYwMDdmZmJlY2JlMGFiOWNkZXwxMDE7OzE0NzQ5OTgzNjU7MjsxNDc0OTExOTY1LjcxNjQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"