series error

test.reb

rebol []

; do %shttpd.reb
; do https://raw.githubusercontent.com/rgchris/Scripts/master/httpd.reb
do https://gist.githubusercontent.com/rgchris/96a02d1a226d0ab2e605914fce6bcf80/raw/f96b8a1b7bb9b9f972f86e45f8d74a404808b747/httpd-renc.reb

server: open [
    scheme: 'httpd 8001 [
        probe request/action
        switch request/action [
            "GET /hello" [
                response/status: 200
                response/type: copy "text/plain"
                response/content: copy "Hello!"
            ]
        ]
    ]
]

wait server