[BUG] Claude Desktop MSIX becomes Modified, NeedsRemediation when CoworkVMService starts

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 installs successfully using the Windows MSIX package, but immediately after Claude is launched and CoworkVMService becomes active, Windows changes the package status from Ok to Modified, NeedsRemediation.

Once this happens, Claude can no longer launch normally. Windows displays a message instructing the user to repair the application from Advanced Options. Repair does not resolve the issue.

The important reproducible observation is that terminating cowork-svc.exe causes the Claude package status to return immediately from Modified, NeedsRemediation to Ok.

The same Claude Desktop application works correctly when installed using the legacy Squirrel/EXE distribution instead of MSIX.

Environment

Windows 11 Pro

Version 25H2

OS Build 26200.8973

MSIX version tested: Claude Desktop 1.24012.11.0

Hyper-V enabled

Virtual Machine Platform enabled

WSL2 enabled

The system has both integrated Intel graphics and a discrete NVIDIA GPU.

Initial Problem

Claude Desktop had previously worked correctly using the Squirrel/EXE installation.

After moving to a newer Claude Desktop installation that included Cowork through the MSIX package, Claude stopped functioning normally.

The application was then completely uninstalled and reinstalled several times while troubleshooting.

Both the normal Claude Setup installer and the direct Enterprise MSIX package were tested.

The problem remained reproducible with the MSIX installation.

Clean MSIX Installation Test

A clean installation of the direct MSIX package was performed.

Immediately after installation, the following command:

Get-AppxPackage Claude

reported:

Status: Ok

This demonstrated that the MSIX package itself installed and registered successfully.

However, after Claude was launched once, the same command reported:

Status: Modified, NeedsRemediation

Windows then prevented Claude from launching normally and displayed a message instructing the user to repair the application.

Repair Attempt

Windows Settings → Apps → Claude → Advanced Options → Repair was attempted.

Repair either failed or reported that the application could not be repaired.

Reinstalling the package did not permanently resolve the problem.

Package Registration and Signature Checks

The installed Claude package was successfully registered by Windows.

The package installation and registration events in the AppX deployment logs completed successfully.

The Cowork service executable was present and its Authenticode signature was checked.

The signature status was:

Valid

The service was registered as:

CoworkVMService

The service executable was installed as part of the Claude MSIX package.

Cowork Service Investigation

CoworkVMService successfully started during normal Claude activation.

The Cowork service log showed successful initialization of the required Windows virtualization components.

The log included successful initialization of HCS and HCN components.

Signature verification initialized successfully.

The Cowork named-pipe server started successfully.

The service reached the state:

Service ready

There was no obvious failure in the Cowork service itself.

Most Important Reproduction

While Claude was in the broken state, the package reported:

Modified, NeedsRemediation

The cowork-svc.exe process was then terminated manually.

Immediately afterwards:

Get-AppxPackage Claude

reported:

Status: Ok

No package repair or reinstall was performed between these two checks.

This behavior was reproducible.

When Cowork was active, the package entered the unhealthy state.

When the Cowork service process was stopped, the package returned to Ok.

This is the strongest indication that the problem is associated with the packaged Cowork service lifecycle or its interaction with Windows AppModel/MSIX package state.

Service Start Behavior

CoworkVMService was registered as a packaged Windows service.

Attempts to manually start it using normal service-management commands produced unusual errors, including:

StartService FAILED 87: The parameter is incorrect.

However, when Claude itself started the packaged service through its normal activation path, the Cowork logs showed that the service did in fact initialize successfully.

Therefore, the service does not appear simply to be failing to start.

Windows Event Logs

The following event channels were inspected:

Microsoft-Windows-AppXDeploymentServer/Operational

Microsoft-Windows-AppModel-Runtime/Admin

Application log

The MSIX installation completed successfully.

Package registration completed successfully.

Windows also successfully parsed the packaged-service declaration.

No clear AppX deployment failure explaining the behavior was found.

The AppModel runtime did record package-state transitions associated with Claude activation.

Claude Application Log

Claude's application log also recorded an Electron GPU-process crash:

GPU process gone

reason: crashed

This may represent a separate issue.

Disabling GPU acceleration for a test launch did not eliminate the MSIX repair problem.

For that reason, the GPU crash should not be assumed to be the cause of the package NeedsRemediation state.

Squirrel/EXE Comparison

The MSIX version was completely removed.

Claude Desktop was then installed using WinGet with the EXE installer type rather than MSIX.

The installation was verified as a Squirrel installation.

Get-AppxPackage Claude

returned no package.

There was no CoworkVMService.

There was no cowork-svc.exe service executable in the application installation.

Claude launched successfully.

Authentication worked normally.

The application remained stable.

The Squirrel installation subsequently updated successfully to a newer Claude Desktop release and continued to work normally.

The currently working Squirrel installation has also updated beyond the MSIX version originally tested without reproducing the MSIX failure.

Current Workaround

Claude Desktop is currently being used successfully through the Squirrel/EXE installation.

The workaround is functional, but Cowork is unavailable because the Squirrel distribution does not install CoworkVMService.

The MSIX version has therefore not been reinstalled again because doing so would disrupt an otherwise working Claude Desktop installation.

Expected Behavior

Installing Claude Desktop using MSIX should result in a package that remains:

Status: Ok

after Claude and Cowork are launched.

CoworkVMService should be able to operate without causing Windows to mark the Claude package as modified or requiring remediation.

Actual Behavior

The MSIX installs successfully and initially reports:

Status: Ok

After Claude launches and CoworkVMService becomes active, Windows changes the package status to:

Modified, NeedsRemediation

Claude subsequently becomes unusable.

Stopping cowork-svc.exe causes the package status to return immediately to:

Ok

Why This Appears Significant

The issue does not appear to be a failed MSIX installation.

The package installs and registers successfully.

CoworkVMService itself also initializes successfully.

The problem appears only after runtime activation.

The reversible relationship between Cowork service activity and the package health state may help isolate the problem.

At this stage I have deliberately avoided claiming whether the underlying cause is a filesystem modification, package-owned registry state, packaged-service lifecycle behavior, Windows AppModel behavior, or another MSIX integrity mechanism.

The reproducible behavior is the key finding.

Additional Diagnostics Available

If useful to Anthropic engineers, I am willing to reproduce the issue again in a controlled test environment and collect targeted diagnostics such as:

Process Monitor traces covering file and registry activity during the exact package-state transition.

Before-and-after snapshots of CoworkVMService registry state.

Package status before and after service startup.

AppModel and AppX deployment event logs.

Cowork service logs.

Package-content hash comparisons if specifically requested.

I would prefer not to reinstall the MSIX version on the currently working environment solely for generic troubleshooting, but I can perform a targeted reproduction if there are specific diagnostics Anthropic would like collected.

What Should Happen?

I want to be able use Claude CoWork

Error Messages/Logs

The primary Windows error shown when attempting to launch the MSIX version of Claude Desktop was:

"You’ll need to go to advanced options for Claude and select Repair. If you’re still having issues with it, reinstall this app or contact your administrator."

When attempting Windows Settings → Apps → Claude → Advanced options → Repair, repair also failed. At different points Windows reported:

"We couldn't repair this app. Try again in a bit."

and, after CoworkVMService remained running:

"We couldn't repair this app because it's currently running."

Immediately after a clean MSIX installation, the package status was healthy:

Get-AppxPackage *Claude* | Select Name, PackageFullName, Version, Status

Name: Claude
Version: 1.24012.11.0
Status: Ok

After launching Claude and CoworkVMService becoming active, the same command reported:

Status: Modified, NeedsRemediation

The corresponding package state-change record showed:

PackageStatus: 2097152

which corresponds to:

0x200000

Attempting to start CoworkVMService manually with PowerShell produced:

Start-Service : Service 'Claude (CoworkVMService)' cannot be started due to the following error: Cannot start service CoworkVMService on computer '.'.

Using sc.exe produced:

[SC] StartService FAILED 87:

The parameter is incorrect.

However, when Claude itself activated CoworkVMService normally, the Cowork service log showed successful initialization rather than a service failure. Relevant entries included:

Claude VM Service starting...
Waiting for configuration from app via 'configure' method...
[HCS] Initializing HCS DLLs...
[HCS] vmcompute.dll loaded successfully
[HCS] computecore.dll loaded successfully
[HCS] Procs initialized, HCS ready
[HCN] Initialized HCN API from computenetwork.dll
[Server] Signature verification initialized
[Server] Starting named pipe server on \\.\pipe\cowork-vm-service
[Server] Named pipe server listening
Service ready. Listening on \\.\pipe\cowork-vm-service

The Authenticode signature of cowork-svc.exe was also checked and returned:

Status: Valid

The AppX deployment log showed that installation itself completed successfully:

Deployment Add operation with target volume C: on Package Claude_1.24012.11.0_x64__pzs8sxrjxfjjc from: (Claude.msix) finished successfully.

Package registration also completed successfully:

Deployment Register operation with target volume C: on Package Claude_1.24012.11.0_x64__pzs8sxrjxfjjc from: (AppxManifest.xml) finished successfully.

The most significant reproducible result was:

1. With cowork-svc.exe running:
   Get-AppxPackage *Claude* reported "Modified, NeedsRemediation".

2. After terminating cowork-svc.exe:
   Get-AppxPackage *Claude* immediately returned to "Ok".

No reinstall or repair was performed between those two checks.

Claude's application log also recorded an Electron GPU-process crash:

GPU process gone:
type: 'GPU'
reason: 'crashed'
exitCode: 101457950
serviceName: 'GPU'

This GPU error may be a separate issue. Testing a launch with GPU acceleration disabled did not eliminate the MSIX/Repair problem.

For comparison, the non-MSIX Squirrel/EXE installation works normally on the same Windows system. It has subsequently updated successfully to a newer Claude Desktop release without reproducing this package-state failure.

Steps to Reproduce

1. Start from a Windows 11 Pro system running Version 25H2, OS Build 26200.8973, with Hyper-V and Virtual Machine Platform enabled.

1. Make sure no previous Claude MSIX package is installed.

1. Install Claude Desktop using the official Windows MSIX package.

1. After installation completes, open PowerShell and verify the package status:

Get-AppxPackage Claude | Select-Object Name, PackageFullName, Version, Status

1. Confirm that the package initially reports:

Status: Ok

1. Launch Claude Desktop normally.

1. Allow Claude to initialize CoworkVMService.

1. After Claude has launched, run the same package-status command again:

Get-AppxPackage Claude | Select-Object Name, PackageFullName, Version, Status

1. Observe that the package status changes to:

Modified, NeedsRemediation

1. Attempt to launch Claude again. Windows displays a message indicating that Claude needs to be repaired from Advanced Options.

1. Open Windows Settings → Apps → Installed apps → Claude → Advanced options → Repair.

1. Observe that Repair does not restore the application to a usable state.

1. Confirm that CoworkVMService exists:

Get-Service Cowork

1. Confirm that the Cowork service can initialize normally through Claude. The Cowork service log shows successful HCS/HCN initialization, successful signature verification, named-pipe startup, and “Service ready.”

1. While the Claude package is in the Modified, NeedsRemediation state, terminate the Cowork service process:

Stop-Process -Name cowork-svc -Force

1. Immediately check the Claude package status again:

Get-AppxPackage Claude | Select-Object Name, PackageFullName, Version, Status

1. Observe that the package status returns to:

Status: Ok

1. Launch Claude again and allow CoworkVMService to start.

1. Observe that the package again transitions to:

Modified, NeedsRemediation

1. Repeat the stop-process test to confirm that stopping cowork-svc.exe returns the package to Status: Ok.

This behavior was reproducible during testing.

For comparison, installing Claude using the legacy EXE/Squirrel installer on the same computer works normally. The Squirrel installation does not register an AppX package, does not install CoworkVMService, and continues to function normally after updating to newer Claude Desktop versions.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Opus 5

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_