Kaltura_Client_Exception thrown

Invalid KS "MGFmMzIwOTZhNjgzYjYxM2EyMzhhNjY4OTFlYmM2MjJhZTRmOGU5M3wxMDE7OzE0OTM1MzY4MTI7MjsxNDkzNDUwNDEyLjU1MTk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"