Error when following the Smart Contract guide

[Niels Mündler]

I followed the Smart Contract guide here: https://meshjs.dev/guides/smart-contract

I have implemented everything exactly as described. Trying to lock funds I get stuck with this error message in the console:

Uncaught (in promise) Deserialization failed in ScriptHash because: Invalid cbor: expected tuple 'hash length' of length 28 but got length Len(0)