discourse/discourse · error · Error

Download failed

Error message

Download failed: ${response.status}

What it means

downloadBlob fetched the URL with same-origin credentials and got a non-ok HTTP response; instead of a blob, it throws with the numeric status. Callers like theme export and download flows use this to surface server-side failures (auth, not-found, server errors) rather than getting an empty or error-page file.

Solutions

  1. Check the status code: 401/403 means authentication or permission issues, 404 means the URL is wrong, 5xx is a server error
  2. Verify the user is logged in and authorized for the resource
  3. Retry the request if the status indicates a transient server error
Defensive patterns

Strategy: try-catch

When it happens

Trigger: Thrown at frontend/discourse/app/lib/download-blob.js:54 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of discourse/discourse@1b2d7253e8 (2026-08-26). Data as JSON: /api/errors/0185046c2fe4cb78. Report an issue: GitHub.

Appendix: source

Thrown at frontend/discourse/app/lib/download-blob.js:54

  }
  a.rel = "noopener";
  document.body.appendChild(a);
  a.click();
  document.body.removeChild(a);
  setTimeout(() => URL.revokeObjectURL(objectUrl), REVOKE_AFTER);
}

// Fetches `url` and triggers a browser download of the response body.
export default async function downloadBlob(
  url,
  { fallbackFilename, fetchOptions } = {}
) {
  const response = await fetch(url, {
    credentials: "same-origin",
    ...fetchOptions,
  });
  if (!response.ok) {
    throw new Error(`Download failed: ${response.status}`);
  }
  triggerBlobDownload(await response.blob(), {
    fallbackFilename,
    contentDisposition: response.headers.get("Content-Disposition"),
  });
}

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