invoke-ai/InvokeAI · error · ExternalProviderRequestError

Failed to download image from DashScope (status {response.st

Error message

Failed to download image from DashScope (status {response.status_code})

What it means

The HTTP request for the generated image completed but returned a non-2xx status. _download_image checks response.ok inside the stream context and raises ExternalProviderRequestError embedding the status code, because the image could not be fetched.

Source

Thrown at invokeai/app/services/external_generation/providers/alibabacloud.py:299

            raise ExternalProviderRequestError(f"DashScope async response contained no images: {output}")

        return ExternalGenerationResult(
            images=images,
            seed_used=request.seed,
            provider_request_id=request_id,
            provider_metadata={"model": request.model.provider_model_id},
        )

    def _download_image(self, url: str) -> PILImageType:
        """Download an image from a URL and return it as a PIL Image, with a size cap."""
        try:
            response = requests.get(url, timeout=_DOWNLOAD_TIMEOUT, stream=True)
        except requests.RequestException as exc:
            raise ExternalProviderRequestError(f"Failed to download image from DashScope: {exc}") from exc

        with response:
            if not response.ok:
                raise ExternalProviderRequestError(
                    f"Failed to download image from DashScope (status {response.status_code})"
                )

            content_length = response.headers.get("Content-Length")
            if content_length is not None:
                try:
                    if int(content_length) > _DOWNLOAD_MAX_BYTES:
                        raise ExternalProviderRequestError(
                            f"DashScope image exceeds {_DOWNLOAD_MAX_BYTES} byte cap (Content-Length={content_length})"
                        )
                except ValueError:
                    pass

            buffer = bytearray()
            for chunk in response.iter_content(chunk_size=64 * 1024):
                if not chunk:
                    continue
                buffer.extend(chunk)

View on GitHub (pinned to 0b6a024f2f)

Solutions

  1. Note the status: 403/404/410 usually means the signed URL expired — regenerate the image rather than re-fetching the old URL
  2. Retry the full generation request to obtain fresh URLs
  3. Ensure you consume results promptly after generation
  4. Check that no proxy/ACL blocks access to the DashScope result-URL hosts
  5. If 5xx, retry after a short delay

Example fix

// before
pil_image = provider._download_image(stale_url)  # 403
// after
result = provider.generate(request)  # fresh URLs each run
pil_image = provider._download_image(result.images[0].url)
Defensive patterns

Strategy: retry

Validate before calling

def validate_provider_config(cfg) -> None:
    if not cfg.external_alibabacloud_api_key:
        raise ValueError("DashScope API key missing")
    if "dashscope" not in (cfg.external_alibabacloud_base_url or "dashscope-intl.aliyuncs.com"):
        raise ValueError("base_url does not look like a DashScope endpoint")

Try / catch

try:
    result = provider.generate(request)
except ExternalProviderRequestError as e:
    if "status 403" in str(e) or "status 404" in str(e) or "status 410" in str(e):
        log.warning("Image URL rejected (%s); regenerating for a fresh URL", e)
        result = provider.generate(request)
    else:
        raise

Prevention

When it happens

Trigger: 403/404 from an expired or region-mismatched signed URL; 403 from CDN hotlink/ACL restrictions; 410 Gone after URL TTL; 5xx from the image CDN.

Common situations: Downloading images long after generation once signed URLs expire; base_url region (intl vs cn) differing from the URL host region; corporate proxy blocking the CDN; transient CDN errors.

Related errors

AI-assisted analysis of invoke-ai/InvokeAI@0b6a024f2f (2026-08-29). Data as JSON: /api/errors/065fab38f5185ba2. Report an issue: GitHub.