Browser pane: page with real-sitekey Cloudflare Turnstile widget crashes GPU process and hangs entire app since desktop 1.24012.1 (Windows, MSIX)

Summary

Since auto-updating 1.22209.3 -> 1.24012.1 (which also migrated my install to MSIX), opening my site https://sitterunleashed.com in the in-app Browser pane kills the Electron GPU process ~2-5 seconds after load, 100% reproducible (6/6). The app never recovers the GPU process; the whole window hangs and must be force-closed. I bisected the trigger to the page's Cloudflare Turnstile widget running with a real production sitekey.

Bisection evidence (all opened in the Browser pane)

• CRASH: https://sitterunleashed.com (Turnstile widget on its contact form)
• OK: the exact same page with TURNSTILE_SITE_KEY removed from the live worker (I control the site; removing the widget stopped the crash, restoring it brings the crash back)
• OK: same page served locally, dev build and production build (dummy Turnstile key)
• OK: static mirror of the live HTML with JS stripped (rules out CSS/fonts/SVG/webp rendering)
• OK: https://get.webgl.org (rules out WebGL generally)
• OK: https://demo.turnstile.workers.dev (demo/test sitekeys evidently skip the heavy challenge path that real keys run)
• OK: google.com and other ordinary sites

Crash signature

Identical every time, in %APPDATA%\Claude\logs\main.log:

[Preview] Created browser preview { serverId: ... }
  ~2-5s later:
GPU process gone: {
  type: 'GPU',
  reason: 'crashed',
  exitCode: 101457950,
  serviceName: 'GPU'
}

then the log goes silent; app hung until manually restarted.

Also reproduces with the app forced onto the integrated GPU, so it is not GPU-vendor specific:

• NVIDIA RTX 5060 Laptop GPU (driver 32.0.15.9201): crashes
• AMD Radeon 610M via Windows per-app "Power saving" preference: crashes

Regression

• 1.22209.0 / 1.22209.3: six Browser pane opens 2026-07-13..07-19, zero crashes (GPU driver unchanged since 2026-04-21).
• 1.24012.1 (installed 2026-07-22): every pane open of the Turnstile page crashes.

Repro

Open any page embedding Turnstile with a real production sitekey in the Browser pane on Windows. My site https://sitterunleashed.com reproduces it; happy to help test a fix.

Environment

• Claude desktop 1.24012.1 (MSIX, Claude_pzs8sxrjxfjjc)
• Claude Code 2.1.217
• Windows 11 Home 26200, 32 GB RAM (20+ GB free at crash)
• No Crashpad minidumps were written. Full main.log available on request.

Impact

Any agent session opening a Turnstile-protected page in the pane takes down the whole app. Turnstile is common on login/contact pages, so this likely affects many users who won't be able to self-diagnose it.

(Diagnosed with Claude Code itself: log analysis plus A/B bisection of the live site.)