Vue okta-hosted-login Sample Project responds with "Unhandled promise rejection"

I cloned, followed all install steps, including replacing {clientId} and {yourOktaDomain} in .samples.config.js with my own Okta values. The custom-login sample worked fine. But the okta-hosted-login sample failed:

"Unhandled promise rejection".
errorCode: "invalid_request"
errorSummary: "The authorization server id is invalid."
message: "The authorization server id is invalid."
name: "OAuthError"

The error is pegged to okta-vue.js:109. The message “[HMR] Waiting for update signal from WDS…” appears in the Console in log.js.

(I got the same type of error when testing another Okta tutorial, “Build a Basic CRUD App with Laravel and Vue” from

Does someone have a suggestion as to how I can track down the cause of this error?

OS X Mojave 10.14.5
node v10.16.0.