Kaltura_Client_Exception thrown

Invalid KS "MWM4MjNlNTVhZmNkOGI5MmE2ODNhYTkyMGI1YjkwOWVhNWQxM2E1ZHwxMDE7OzE0ODQ4NDk4MjA7MjsxNDg0NzYzNDIwLjE4MTk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"