responsively-org/responsively-app · info

iframe error:

Error message

iframe error:

What it means

This is not a throw but a console.warn emitted in didFailLoadHandler when a webContents 'did-fail-load' event reports isMainFrame === false. Sub-frame (iframe) load failures such as CSP-blocked resources or X-Frame-Only pages are deliberately demoted to console output so the renderer only shows a full error overlay for main-frame failures. Seeing 'iframe error:' in the console means an embedded frame failed to load, not the page itself.

Source

Thrown at desktop-app/src/renderer/components/Previewer/Device/index.tsx:402

    handlerRemovers.push(() => {
      webview.removeEventListener('did-stop-loading', didStopLoadingHandler);
    });

    const didFailLoadHandler = ({
      errorCode,
      errorDescription,
      isMainFrame,
    }: Electron.DidFailLoadEvent) => {
      if (errorCode === -3) {
        // Aborted error, can be ignored
        return;
      }

      // Only show error overlay for main frame errors
      // Iframe errors (like CSP violations) should only go to console
      if (!isMainFrame) {
        // eslint-disable-next-line no-console
        console.warn('iframe error:', errorCode, errorDescription);
        return;
      }

      setError({
        code: errorCode,
        description: errorDescription,
      });
    };
    webview.addEventListener('did-fail-load', didFailLoadHandler);
    handlerRemovers.push(() => {
      webview.removeEventListener('did-fail-load', didFailLoadHandler);
    });

    if (!isPrimary) {
      setTimeout(() => {
        webview.addEventListener('dom-ready', () => {
          window.electron.ipcRenderer.invoke<
            DisableDefaultWindowOpenHandlerArgs,

View on GitHub (pinned to e5623c5a70)

Solutions

1. Verify the main page still renders; if it does, this warning is expected and ignorable
2. If the iframe content is required, fix the source page's CSP/X-Frame-Options headers to allow embedding
3. Whitelist known-noisy sub-frame error codes in the warn filter if console spam is an issue
4. If the overlay incorrectly appears, check that isMainFrame is being read from the event args and not defaulting

webContents.on('did-fail-load', (event, errorCode, errorDescription, validatedURL, isMainFrame) => {
  if (typeof isMainFrame !== 'boolean') return;
  if (!isMainFrame) {
    console.warn('iframe error:', errorCode, errorDescription);
    return;
  }
  setError({ code: errorCode, description: errorDescription });
});

function isMainFrameLoadFailure(args: { isMainFrame?: boolean }): args is { isMainFrame: true } {
  return args.isMainFrame === true;
}

When it happens

Trigger: An iframe inside the loaded page fails with codes like ERR_BLOCKED_BY_RESPONSE (CSP frame-ancestors), ERR_CERT errors on embedded resources, or aborted subresource loads; the handler receives (event, errorCode, errorDescription, validatedURL, isMainFrame=false).

Common situations: Embedding sites that send CSP frame-ancestors or X-Frame-Options DENY, mixed-content blocked iframes, ad/analytics iframes failing in offline mode, previewing pages with third-party embeds.

Related errors

• "mainWindow" is not defined

AI-assisted analysis of responsively-org/responsively-app@e5623c5a70 (2026-08-31). Data as JSON: /api/errors/e2bf956dd5c5f8f6. Report an issue: GitHub.