Kaltura_Client_Exception thrown

Invalid KS "MTIzMDkwNjk2ZWY0NWUyMTFkZDc5ZTk4YjQ0ZDY5ODJhMzVjMDM1YXwxMDE7OzE0OTU3MDEwOTU7MjsxNDk1NjE0Njk1Ljg2NTU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"