sos-nextjs/components/errorDisplay.js

const errorMessages = {
  404: {title: 'Page not found', message: 'Unfortunately that page could not be found.  If you followed a link to get here, please let the owner of the link know that they need to update it.'},
  [undefined]: {title: 'Unknown error', message: "We're not exactly sure what happened"}
}

export default function ErrorDisplay({error}){
  const defaults = errorMessages[error.status]

  return (
    <>
      <h2>{error.name || defaults.title}</h2>
      <p>{error.message || defaults.message}</p>
      {process.env.NODE_ENV === 'development' && (
        <pre>
          {JSON.stringify(error, null, 2)}
        </pre>
      )}
    </>
  )
}