Failures come back straight away

When part of a page asked the portal for something it could not serve — a file from a component that was restarting, say — the "no" was sent back by a slower internal route than the original question travelled on. Usually that was fine. Occasionally the answer was simply lost, and whatever was waiting for it waited a full minute, or forever.

Failure answers now come back the same way the request went out. Something that cannot be served says so immediately, so a slow corner of a page stays a slow corner instead of holding the rest up.