Kaltura_Client_Exception thrown

Invalid KS "YjBhMWQxZGMwMjYxNGVkNzVmOWYxNmVkNDhjZmY5Zjk4MzU2NTg3NnwxMDE7OzE0NzUxNjQwMjE7MjsxNDc1MDc3NjIxLjY5NDQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"