grafana/k6 · error

updating page frame sessions to offline: %w

Error message

updating page frame sessions to offline: %w

What it means

Page.updateOffline applies network offline emulation (Network.emulateNetworkConditions with offline=true) to every frame session, and this error means at least one frame session's CDP call failed. Because it iterates all frame sessions, a single detached iframe session is enough to fail the whole operation.

Source

Thrown at internal/js/modules/k6/browser/common/page.go:878

				"sid:%v tid:%v wid:%v err:%v",
				p.sessionID(), fs.targetID, fs.windowID, err)

			return err
		}
	}

	return nil
}

func (p *Page) updateOffline() error {
	p.logger.Debugf("Page:updateOffline", "sid:%v", p.sessionID())

	p.frameSessionsMu.RLock()
	defer p.frameSessionsMu.RUnlock()

	for _, fs := range p.frameSessions {
		if err := fs.updateOffline(false); err != nil {
			return fmt.Errorf("updating page frame sessions to offline: %w", err)
		}
	}

	return nil
}

func (p *Page) updateHTTPCredentials() error {
	p.logger.Debugf("Page:updateHttpCredentials", "sid:%v", p.sessionID())

	p.frameSessionsMu.RLock()
	defer p.frameSessionsMu.RUnlock()

	for _, fs := range p.frameSessions {
		if err := fs.updateHTTPCredentials(false); err != nil {
			return err
		}
	}

View on GitHub (pinned to 93accf6570)

Solutions

1. Apply offline emulation on the browser context at creation (newContext({offline: true})) rather than flipping it mid-navigation
2. Call page.setOffline only after the page reaches a stable lifecycle state
3. Ensure the page and its iframes are not navigating or closing when the call is made
4. Retry once if it raced with frame attachment

Example fix

// before
await page.goto('https://example.com/');
await page.setOffline(true); // iframe sessions may be in flux

// after
const context = browser.newContext({ offline: true });
const page = context.newPage();
await page.goto('https://example.com/');

if (page.isClosed()) throw new Error('cannot toggle offline on closed page');

try {
  await page.setOffline(true);
} catch (e) {
  if (/updating page frame sessions to offline/.test(e.message)) { /* settle and retry once */ }
  else throw e;
}

When it happens

Trigger: page.setOffline(true/false) (or constructing a browser context with offline emulation) on a page containing iframes whose sessions are mid-attach or already detached; page closing concurrently.

Common situations: Toggling offline to simulate network loss on a page with third-party iframes; combining offline emulation with page.reload() so frames re-attach while the call runs; running against a closing/crashed browser.

Related errors

• errorText
• getting iframe frame: %w
• getting remote node %q: %w
• updating extra HTTP headers: %w
• updating offline mode for frame %v: %w

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/821753f6e1cba213. Report an issue: GitHub.