Windows Store (MSIX) install: bundled Claude Code can never update - anti-tamper check flags MSIX AppData virtualization as a plant (PlantDetectedError)

## Environment

• Claude Desktop: 1.26832.0.0, Microsoft Store install (MSIX package Claude_pzs8sxrjxfjjc). Also reproduced on the previous build 1.25927.0.0.
• OS: Windows 11 Pro, build 10.0.26200
• Bundled Claude Code: stuck at 2.1.217 (current release at time of writing: 2.1.224)

Summary

On a Microsoft Store install, the Desktop app's embedded Claude Code updater ("CCD") fails on every launch with PlantDetectedError and permanently falls back to the last successfully installed version (2.1.217 on this machine). The failure has repeated on every attempt since at least 2026-08-05 and survives app updates. There is no user-visible error; the only symptom is that Code sessions silently run an increasingly outdated version.

The cause appears to be a conflict between the updater's junction/plant detection and MSIX AppData virtualization, which is present on every Store install by design.

Details

MSIX packages virtualize %APPDATA%. Writes by the app to:

C:\Users\<user>\AppData\Roaming\Claude\...

are redirected by Windows to the package container:

C:\Users\<user>\AppData\Local\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\...

When CCD downloads a new Claude Code version, its anti-tamper check resolves the target directory AppData\Roaming\Claude\claude-code\<version>, sees the substitute-name redirect created by the OS-level virtualization, classifies it as a planted junction, and aborts:

2026-08-07 18:14:08 [error] [CCD] Download attempt 3/3 failed [PlantDetectedError]:
Private dir leaf redirects (junction/substitute-name plant):
C:\Users\ixs\AppData\Roaming\Claude\claude-code\2.1.222

All 3 download attempts fail identically, the version directory is left behind empty, and the app falls back to 2.1.217. The profile directory now looks like this:

claude-code\2.1.217  -> claude.exe present (in use)
claude-code\2.1.221  -> EMPTY (failed 2026-08-05, app build 1.25927.0.0)
claude-code\2.1.222  -> EMPTY (failed 2026-08-07, app build 1.26832.0.0)

Note the updater already knows it is running from a Store package:

2026-08-07 16:21:28 [info] [updater] MSIX detected: windowsStore=true, appPathMatch=true,
source=windowsStore, exe=C:\Program Files\WindowsApps\Claude_1.26832.0...

so the plant check and the MSIX detection are drawing opposite conclusions about the same redirect.

Full stack trace (from Roaming\Claude\logs\main.log)

2026-08-05 01:54:07 [error] [CCD] Download attempt 1/3 failed [PlantDetectedError]:
Private dir leaf redirects (junction/substitute-name plant):
C:\Users\ixs\AppData\Roaming\Claude\claude-code\2.1.221
    at $n (...\app.asar\.vite\build\index.chunk-CK51t2rJ.js:12:14339)
    at async er (...\app.asar\.vite\build\index.chunk-CK51t2rJ.js:12:14921)
    at async Object.tr (...\app.asar\.vite\build\index.chunk-CK51t2rJ.js:12:15304)
    at async ae.downloadBinaryForTarget (...\app.asar\.vite\build\index2.chunk-B-Og44Xu.js:1:11030)
    at async ae.prepareForTarget (...\app.asar\.vite\build\index2.chunk-B-Og44Xu.js:1:14711)
    at async ae.prepare (...\app.asar\.vite\build\index2.chunk-B-Og44Xu.js:1:22030)
    at async Object.prepare (...\app.asar\.vite\build\index.chunk-4MCuNsI1.js:78:39416)
    at async ...\app.asar\.vite\build\index.chunk-CeSX0peY.js:1:155192
    at async Session.<anonymous> (node:electron/js2c/browser_init:2:119861)
  name: 'PlantDetectedError'

Steps to reproduce

1. Install Claude Desktop from the Microsoft Store on Windows 11.
2. Launch the app and start any Claude Code session.
3. Watch AppData\Roaming\Claude\logs\main.log (or the merged view under LocalCache\Roaming): every launch logs 3/3 failed CCD download attempts with PlantDetectedError.
4. claude-code\<new-version> directories accumulate empty; the session keeps running the old binary.

Expected behavior

The updater should recognize the MSIX VFS redirect as legitimate on Store installs (it already logs windowsStore=true) and either resolve the real LocalCache path before the leaf-redirect check or exempt the package-virtualized profile from junction plant detection.

Additional notes

• Because the check fails identically every launch, Store installs are effectively version-pinned forever; the gap to current will keep widening.
• Easy to misdiagnose: a standalone claude.exe on PATH answers claude --version with the current version while Desktop sessions actually run the stale binary. Verifying requires checking the parent process chain of a running session.
• MSIX layering also means processes inside the container see a merged Roaming\Claude view, while outside processes see only a thin outer layer, which may affect any fix that copies profile files.

07:33:11 UTC  last PlantDetectedError (build 1.26832.0, target 2.1.222)
07:33:48 UTC  [updater] Update downloaded and ready to install  →  1.28929.0
07:34:47 UTC  [CCD] Installed at %APPDATA%\Claude\claude-code\2.1.227\claude.exe
07:34:53 UTC  [CCD] Wrote SDK version file: 2.1.227

PlantDetectedError: Private dir leaf redirects
(junction/substitute-name plant)

C:\Users\<user>\AppData\Local\Claude-3p\
claude-code-vm\2.1.227

C:\Users\<user>\AppData\Local\Packages\
Claude_pzs8sxrjxfjjc\LocalCache\Local\Claude-3p\
claude-code-vm\2.1.227

windowsStore=true
appPathMatch=true
source=windowsStore