jackwener/OpenCLI · error · CommandExecutionError

Midjourney browser-context media fetch failed: ${errorMessag

Error message

Midjourney browser-context media fetch failed: ${errorMessage(error)}

What it means

This error wraps any failure that occurs while executing an in-page fetch inside the Midjourney browser context (page.evaluate) to download media into a window buffer. If the browser-side fetch itself throws (navigation, execution context destroyed, page closed, or fetch rejection), the raw error is rethrown as a CommandExecutionError with a normalized message via errorMessage(error).

Source

Thrown at clis/midjourney/utils.js:554

    let payload;
    try {
      payload = unwrapEvaluateResult(await page.evaluate(async (mediaUrl, key) => {
        // CDN is public but Cloudflare-protected. Browser-origin fetch succeeds
        // with default same-origin credential mode; forcing cross-origin cookies
        // turns it into a credentialed CORS request and Midjourney rejects it.
        const response = await fetch(mediaUrl);
        if (!response.ok) return { ok: false, status: response.status, type: response.headers.get('content-type') || '' };
        const bytes = new Uint8Array(await response.arrayBuffer());
        window[key] = bytes;
        return {
          ok: true,
          status: response.status,
          type: response.headers.get('content-type') || '',
          size: bytes.length,
        };
      }, url, transferKey));
    } catch (error) {
      throw new CommandExecutionError(`Midjourney browser-context media fetch failed: ${errorMessage(error)}`);
    }
    if (!payload || typeof payload !== 'object' || !payload.ok) {
      throw new CommandExecutionError(`Midjourney media download failed: HTTP ${payload?.status ?? 0} from ${url}`);
    }
    if (!String(payload.type || '').startsWith(expectedMimePrefix)) {
      throw new CommandExecutionError(`Midjourney media download returned unexpected content type "${payload.type || 'unknown'}"`);
    }
    const size = Number(payload.size);
    if (!Number.isInteger(size) || size <= 0) {
      throw new CommandExecutionError(`Midjourney media download returned an empty file from ${url}`);
    }

    // Returning a complete base64 file in one Browser Bridge response can
    // exceed the daemon message limit. Pull it out in bounded chunks instead.
    const parts = [];
    const chunkSize = 96 * 1024;
    for (let offset = 0; offset < size; offset += chunkSize) {
      const base64 = unwrapEvaluateResult(await page.evaluate((key, start, length) => {

View on GitHub (pinned to 49907e53dc)

Solutions

1. Retry the command; transient browser/network failures usually resolve.
2. Verify the media URL is still valid (CDN links can expire).
3. Ensure the browser page/browser bridge stays open for the duration of the download.
4. Check proxy/firewall settings affecting the headless browser.

Example fix

// before
downloadMedia(page, expiredUrl);
// after
const freshUrl = await resolveFreshMediaUrl(jobId);
downloadMedia(page, freshUrl);

if (page.isClosed()) throw new Error('Browser page closed; reopen before downloading');

try {
  await downloadMedia(page, url);
} catch (err) {
  if (/browser-context media fetch failed/.test(err.message)) {
    page = await newPage(browser); // reopen page and retry once
    await downloadMedia(page, url);
  } else throw err;
}

When it happens

Trigger: The browser page navigates away or its execution context is destroyed mid-fetch; the in-page fetch to the CDN URL throws (network error, CORS/blocked request, invalid URL); the browser bridge page is closed before the transfer completes.

Common situations: Fetching media right after the job page was closed; CDN URLs that have expired; proxy or network interruptions inside the headless browser; automation races where the page is reused concurrently.

Related errors

• Claude whoami failed: ${result.detail}
• Jike identity probe failed: ${probe.detail}
• Twitter device-follow fetch failed: ${data.detail || 'unknow
• Zhihu answer detail request failed: ${err instanceof Error ?
• Batch fetch failed for ${urls[i]}: ${(r as { error: string }

AI-assisted analysis of jackwener/OpenCLI@49907e53dc (2026-08-29). Data as JSON: /api/errors/31f6e9fc40219451. Report an issue: GitHub.