bundle is a 404 when running npm run dev-script

[michielbdejong]

npm run dev-script starts a web server on port 3001, but the browser then says solid-auth-fetcher-bundle.js is a 404.
Running npm run build works around that, but then the error in the browser console is:

solid-auth-fetcher.bundle.js:144 Uncaught (in promise) Error: schema is invalid:
 should have required property '.oidcIssuer',
 should have required property '.webId',
 should match exactly one schema in oneOf
    at Object.e.default (solid-auth-fetcher.bundle.js:144)
    at f.loginHelper (solid-auth-fetcher.bundle.js:205)
    at f.login (solid-auth-fetcher.bundle.js:205)
    at Object.e.login (solid-auth-fetcher.bundle.js:190)