Remote validation does not work

[jeswr]

On the page https://solid-client-identifier-helper.vercel.app/validator copy/pasting the json contents to validate works; but trying to use the fetch and validate function against a remote url (e.g. https://query.linkeddatafragments.org/solid-client-id.jsonld) fails with
.

Looking at my network requests that action does a POST request to https://solid-client-identifier-helper.vercel.app/api/validate-remote-document?documentIri=https://query.linkeddatafragments.org/solid-client-id.jsonld with an empty payload and gets a 500 response code.

[jeswr]

At the same time as fixing this, it would also be really nice if the response headers for the Client Identifier Document could be validated. In particular, the content-type should be validated to ensure it is of type application/ld+json as opposed to something like an octet-stream.