Kaltura_Client_Exception thrown

Invalid KS "YjUzYWU3YTFiZDZkNjY3MWRjOTg4NmYxODBhMGVlNjdkYmY4ZTk5Y3wxMDE7OzE1MDA2NTY2OTE7MjsxNTAwNTcwMjkxLjEyMTE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"