Zusammenfassung
A condition in the request headers evaluated to false on the server.
Wann er auftritt
Returned when If-Match / If-Unmodified-Since preconditions are not met.
Häufige Ursachen
- Resource changed since the ETag was fetched
- Stale If-Match / If-Unmodified-Since value
Lösung
- Refetch the current ETag and retry
- Remove the failing precondition if not needed
Grundlage in der Spezifikation