Kaltura_Client_Exception thrown

Invalid KS "MWUwYTI0ZTM4MjE3ODBjNjg2NWVkOWEzOTI4NzY2MzJhMzk4ZmU5YnwxMDE7OzE0OTM1NTA2NzA7MjsxNDkzNDY0MjcwLjgyMjg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"