Kaltura_Client_Exception thrown

Invalid KS "YWVhYWZhZjY4Y2Y4ZDdmM2JiYWU0NzU1YTBiY2IwM2MxNWUxNmU5OHwxMDE7OzE0OTg3OTAwODI7MjsxNDk4NzAzNjgyLjQyNjI7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"