Kaltura_Client_Exception thrown

Invalid KS "YTU5MmRmYTk5ZWQ4OGFlN2VmOTcxZmY3YzExZmU1YWM4OGYzOTNlYnwxMDE7OzE0NzUyMTM0MTU7MjsxNDc1MTI3MDE1LjkxMjM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"