Kaltura_Client_Exception thrown

Invalid KS "MmFkZDEzNDkxYTNlZjA5YjI4ZTM5ZjhmM2FkOWM5ZGJhYTk4Yzc1NnwxMDE7OzE0NzUzNzg3OTA7MjsxNDc1MjkyMzkwLjE1NTc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"