Kaltura_Client_Exception thrown

Invalid KS "MTE1ZTBkMTA1NjRiYTUyOWQ1MjIzYTAyZWU4Y2NjN2JmN2VlNWFhMXwxMDE7OzE0NzUxMzMwOTc7MjsxNDc1MDQ2Njk3LjIyNzg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"