Kaltura_Client_Exception thrown

Invalid KS "MzViN2VjOTZkODViYTVmNmQ0MDIzM2IzOTcwZmVmZGIyMmQxZDBjZXwxMDE7OzE0OTA3MDY2Mzg7MjsxNDkwNjIwMjM4LjMzMTQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"