overleaf/overleaf · error · ReadError

error reading file from S3

Error message

error reading file from S3

What it means

Thrown by S3Persistor.getObjectStream when the GetObjectCommand fails (missing key, no read permission, or SDK/network error); the abort controller is triggered to cancel any partial transfer and the raw error is wrapped into a ReadError with bucket/key context.

Source

Thrown at libraries/object-persistor/src/S3Persistor.js:251

    }
    const observer = new PersistorHelper.ObserverStream({
      metric: 's3.ingress', // ingress from S3 to us
      bucket: bucketName,
    })

    const abortController = new AbortController()
    let stream, contentEncoding
    try {
      const { Body, ContentEncoding } = await this._getClientForBucket(
        bucketName
      ).send(new GetObjectCommand(params), {
        abortSignal: abortController.signal,
      })
      stream = Body
      contentEncoding = ContentEncoding
    } catch (err) {
      abortController.abort()
      throw PersistorHelper.wrapError(
        err,
        'error reading file from S3',
        { bucketName, key, opts },
        ReadError
      )
    }
    // Return a PassThrough stream with a minimal interface. It will buffer until the caller starts reading. It will emit errors from the source stream (Stream.pipeline passes errors along).
    const pass = new PassThrough()
    const transformer = []
    if (contentEncoding === 'gzip' && opts.autoGunzip) {
      transformer.push(zlib.createGunzip())
    }
    // @ts-ignore stream (Body) can be undefined in GetObjectCommand
    pipeline(stream, observer, ...transformer, pass, err => {
      if (err) {
        abortController.abort()
      }
    })

View on GitHub (pinned to 28ad3b03b7)

Solutions

1. Treat wrapped NotFoundError (S3 NoSuchKey) as a missing object: regenerate or re-upload it
2. Verify bucket read permissions and the exact key including prefixes
3. Check S3/network health and SDK credentials
4. Retry transient S3 5xx or timeout failures with backoff

When it happens

Trigger: Thrown at libraries/object-persistor/src/S3Persistor.js:251 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of overleaf/overleaf@28ad3b03b7 (2026-09-03). Data as JSON: /api/errors/fca1cadbb7a5063f. Report an issue: GitHub.