Error - worker: Hello World Rust

I am getting the following error
500 Internal Server Error

worker.js:33 Uncaught (in promise) RuntimeError: unreachable
    at wasm-function[128]:0x1d22b
    at wasm-function[240]:0x20547
    at wasm-function[259]:0x20944
    at wasm-function[60]:0x1823a
    at wasm-function[171]:0x1ebed
    at __exports.parse (worker.js:33:18)
    at handleRequest (worker.js:110:20)

when trying to try this sample