Kaltura_Client_Exception thrown

Invalid KS "YTkzZGQyOTY5ODJmYzY4MjUwOTI1N2ZiNGI2ODY4ZjYyMjMwZGFlZXwxMDE7OzE0NzUyMDE3MTI7MjsxNDc1MTE1MzEyLjM0NTc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"