File changed since you read it

HTTP 412 · etag-mismatch — ← all Webpath errors

An If-Match precondition failed: the file changed (or does not exist).

How to recover. Re-read the file and retry your write with the current ETag.

Example response

{
  "type": "https://muse.as/a/webpath/errors/etag-mismatch",
  "title": "File changed since you read it",
  "status": 412,
  "detail": "Re-read the file and retry your write with the current ETag."
}

This page documents the etag-mismatch error type returned in Webpath RFC 7807 application/problem+json responses. The machine-readable detail field carries a recovery hint you can show a user verbatim — see the Spec §12 and API Reference.