[BUG] Claude Desktop 1.6259 (MSIX) - rootfs.vhdx download fails repeatedly, Code tab unusable

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?

Claude Desktop on Windows 11 (MSIX from Microsoft Store) cannot complete the rootfs.vhdx VM download. Every time I click the Code tab, the app starts downloading rootfs.vhdx.zst, reaches around 15-20% (~400MB out of 2.2GB), and then the download silently stops. The window then closes silently with no error.

On the next launch, the download restarts from 0%, never resuming. This loop has repeated 6+ times across multiple sessions.

The bundle directory shows partial files (rootfs.vhdx ~1.7GB, rootfs.vhdx.zst ~414MB) but the VM never actually starts. The Code tab shows gray skeleton boxes that never load.

Tested on:

• Version 1.5354.0 - failed
• Version 1.6259.0 - same failure (auto-updated overnight)

What I tried that did NOT fix it:

• Full uninstall + reinstall via Microsoft Store
• Deleted %LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\vm_bundles
• Added Windows Defender exclusions for Claude paths and processes
• Disabled all background scheduled tasks that touch Claude
• Killed all Claude processes before each retry

Claude Code CLI (v2.1.126) works perfectly on the same machine.

What Should Happen?

Code tab should load. The rootfs.vhdx download should either complete successfully, or resume from where it stopped on next launch instead of restarting from 0%.

Error Messages/Logs

Steps to Reproduce

claude.ai-web.log
cowork_vm_node.log

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.126 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

This bug is specifically about the Claude Desktop app on Windows (MSIX 1.6259.0.0), NOT about the Claude Code CLI. The CLI works perfectly on the same machine.

The Code tab in Claude Desktop is unusable because rootfs.vhdx never finishes downloading. The download starts, reaches ~15-20%, the app window closes silently, and on the next launch the download restarts from 0% instead of resuming.

Related GitHub issues that describe similar/same problem:

• #55946 (rootfs.vhdx commit fails on MSIX 3P mode)
• #32162 (rootfs.vhdx download loop)
• #32147 (rootfs.vhdx detected as missing but download never initiates)

I am attaching main.log and cowork_vm_node.log from the latest crash session.

Logs path:
C:\Users\USER\AppData\Local\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\logs\