Kaltura_Client_Exception thrown

Invalid KS "MWIxN2VhZGIyNTk3OWZkODU2NjM4YTIxZTVhZDA2NDdhNTY4YTE2OHwxMDE7OzE0NzQ5MDA2NDQ7MjsxNDc0ODE0MjQ0LjAwMTM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"