Kaltura_Client_Exception thrown

Invalid KS "MTNmYzgyNzE3NmUzMWFmZDg5YjFjYjAyNjY3NGZlMmEwMDRjOTJlNHwxMDE7OzE0Njk0Nzk5MTg7MjsxNDY5MzkzNTE4LjUzMTk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"