[BUG] Claude Desktop 1.13576.0.0 (Windows MSIX) — startup OOM, main process RAM climbs to ~4.2GB then app dies ~15-20s after launch, all tabs affected, known workarounds ineffective

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

What's Wrong?

Claude Desktop enters a crash loop on Windows 11. The window opens and renders normally, then after ~15–20 seconds the entire app self-terminates. Independent of which tab is clicked (Chat, Cowork, Code) — not tab-specific. In Task Manager the main Claude.exe working set climbs rapidly and the app dies right around ~4,200 MB, consistent with hitting the ~4GB V8 heap ceiling. Reproduces every launch.
Version / Environment

App version: 1.13576.0.0 (MSIX, package Claude_pzs8sxrjxfjjc)
OS: Windows 11, build 10.0.26200.8655
Installed from: official MSIX (https://claude.ai/api/desktop/win32/x64/msix/latest/redirect)
System RAM: [RAM]GB (system hits ~95% usage at crash point)

Steps to Reproduce

Launch Claude Desktop
App renders normally
Within ~15–20s, main Claude.exe RAM climbs to ~4.2GB
App self-terminates, no visible error
Repeats every launch

Workarounds tried — none resolved it:

Full uninstall + reinstall
--disable-gpu and --disable-software-rasterizer
Full Remove-AppxPackage -AllUsers + clean MSIX reinstall (fresh data container)
New empty session instead of restoring previous sessions
--disable-background-networking — did not help (RAM still climbs)
--disable-background-networking --js-flags=--max-old-space-size=2048 — did not help (RAM still climbs to ~4.2GB and dies)

Notes

Nothing written to the Windows Application event log for Claude (no Application Error / WER entry) — controlled self-termination on OOM rather than a hard crash.
No .log files present under the package's LocalCache data folder.
Crash at ~4.2GB matches the ~3.6GB V8-heap-ceiling OOM in #48942 (skills sync memory leak); the --disable-background-networking workaround from #65550 is ineffective here.
Official MSIX latest redirect serves only 1.13576.0.0; version-specific redirect paths return HTTP 403 — rolling back to a known-good build via the official channel is not possible.

Requested

Fix for the startup memory leak in 1.13576.0.0
A supported way to install a previous known-good build (e.g. 1.10628.2.0) while the fix is pending

What Should Happen?

Claude Desktop should launch and remain stable. The main process memory should stabilize at a normal level instead of climbing uncontrollably until the app is killed.

Error Messages/Logs

No error message is shown. Nothing is written to the Windows Application event log for Claude (no Application Error / Windows Error Reporting entry), and no .log files exist under the package's LocalCache data folder. The app silently self-terminates. The only observable signal is in Task Manager: the main Claude.exe working set climbs to ~4,200 MB within ~15-20 seconds, then the process dies.

Steps to Reproduce

1. Launch Claude Desktop (v1.13576.0.0, Windows MSIX)
2. The window opens and renders normally
3. Within ~15-20 seconds, the main Claude.exe process memory climbs rapidly to ~4,200 MB
4. The entire app self-terminates with no visible error
5. Crash reproduces on every relaunch, independent of which tab is clicked (Chat, Cowork, or Code) — it is NOT tab-specific

Workarounds already tried, none resolved it:

• Full uninstall + reinstall
• --disable-gpu and --disable-software-rasterizer launch flags
• Full Remove-AppxPackage -AllUsers + clean MSIX reinstall (fresh data container)
• Launching a new empty session instead of restoring previous sessions
• --disable-background-networking → did not help (RAM still climbs)
• --disable-background-networking --js-flags=--max-old-space-size=2048 → did not help (RAM still climbs to ~4.2GB and dies)

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

A previous build worked the same morning before the auto-update to 1.13576.0.0. Exact prior version not captured, but the official MSIX "latest" redirect now serves only 1.13576.0.0 and version-specific redirect paths return HTTP 403, so rolling back is not possible.

Claude Code Version

Claude Desktop app 1.13576.0.0 (MSIX, package Claude_pzs8sxrjxfjjc). This is the Desktop application, not the Claude Code CLI.

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

• Crash at ~4.2GB matches the ~3.6GB V8 heap ceiling OOM pattern in #48942 (skills sync memory leak) and the RSS-climb pattern in #65550.
• The --max-old-space-size cap not preventing the climb suggests growth may be in native/external (ArrayBuffer-style) allocations, not only V8 old space.
• System RAM reaches ~95% at the crash point.
• Requested: (1) fix for the startup memory leak in 1.13576.0.0, (2) a supported way to install a previous known-good build (e.g. 1.10628.2.0) while the fix is pending.