[Desktop/Windows] Main webview renderer crashes on launch (0xC0000005) since 2.19675.0, app unusable

Summary

Since the Microsoft Store update to Claude Desktop 2.19675.0 (MSIX) on 2026-10-01, the app fails to open on Windows 10. Every launch, the main webview renderer crashes with exitCode: -1073741819 (0xC0000005, access violation), the app reloads it 4 times, then gives up with "Claude crashed repeatedly. Try restarting the app. If it keeps crashing, reinstall Claude from the Microsoft Store...". Rebooting the machine does not help.

Environment

| | |
|---|---|
| App | Claude Desktop 2.19675.0 (MSIX / Microsoft Store) |
| Desktop commit | 5706e5524dba58b23e105c31c358df8ab0a95852 |
| Web commit loaded | aa6da7d0d3a86c1fc9a5ff8bd8d97440c4a8a37a |
| OS | Windows 10 Pro 22H2, build 19045 |
| GPU | NVIDIA GeForce RTX 3060 Ti, driver 32.0.16.1692 (2026-09-03) |
| RAM | 32 GB |

Regression timeline (from %LOCALAPPDATA%\Claude\Logs\main.log)

| Time (local, UTC-3) | Event |
|---|---|
| 2026-10-01 18:25 | 2.19675.0 installed by Store auto-update |
| 2026-10-01 18:36 | First Main webview render process gone ever recorded in this log |
| Before 2026-10-01 | 0 occurrences of this crash |
| 2026-10-01 → 2026-10-03 | 51 crashes (5 / 24 / 22 per day) |

The crash starts 11 minutes after the update, with no other change on the machine.

Log excerpt (every launch looks the same)

[info] Starting app {
[info] Loaded https://claude.ai (web commit aa6da7d0..., desktop commit 5706e552...)
[info] [LocalPluginsReader] Found 11 local plugins
[info] mainView backgroundThrottling restored (... boot: done ...)
[warn] Blocked permission check {            <- repeated ~27 times
[info] Media permission probe {
  result: 'denied', via: 'media_access_check', captureKind: 'video',
  requestingSite: 'hcaptcha', requestingOrigin: 'https://newassets.hcaptcha.com',
  topFrameUrl: 'https://claude.ai', isMainFrame: false, isMainView: true, ...
[info] Main webview render process gone: { reason: 'crashed', exitCode: -1073741819 }
[error] Sentry caught: {
... (reload, same sequence) x4
[info] Render process gone reload cap reached; not reloading again

The renderer dies about 1-3 s after claude.ai loads. In the captured launches, the last event before the crash is the hCaptcha iframe's video media_access_check. This is a correlation, not a confirmed cause.

Steps to reproduce

1. Windows 10 22H2 with Claude Desktop 2.19675.0 from the Microsoft Store, signed in.
2. Launch the app.
3. The window appears briefly, the renderer crashes 4 times and the "crashed repeatedly" dialog is shown.

Happens on every launch. One launch out of about 10 succeeded, so it may be timing-dependent.

What was ruled out

| Test | Result |
|---|---|
| Reboot | Still crashes |
| Moved GPUCache, Code Cache, Cache, DawnGraphiteCache, DawnWebGPUCache, Session Storage out of the profile | Still crashes |
| Launched with --disable-gpu --disable-gpu-compositing | Still crashes (not verified that the MSIX launcher forwarded the flags) |
| Moved Local Storage, IndexedDB, WebStorage, Partitions, Preferences, Local State, window-state.json out | Still crashes |
| claude_desktop_config.json reduced to {"preferences":{}} | Still crashes |
| Fresh, empty profile (signed out) | Opens normally, no crash |
| Third-party DLL injection (overlays, hooks) | None found in the minidump (only NVIDIA Overlay running) |
| Event Viewer Application Error (ID 1000) for Claude.exe | None (only the renderer dies, not the main process) |

So the crash shows up only in the signed-in state and does not depend on local caches or settings. Combined with the timing, this points to the 2.19675.0 build (or the web bundle it loads) rather than local corruption.

Other notes from the same sessions

• MaxListenersExceededWarning: 11 coworkHipaaRestricted listeners added to [EventEmitter] on every launch (probably unrelated, reported for completeness).

Impact

The desktop app has been unusable since 2026-10-01. The workaround is claude.ai in a browser and the Claude Code CLI, both of which work on the same machine.