[BUG] Recurring "Can't open this app" on Windows — MSIX re-registration failure persists across multiple related issues with no official fix

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 repeatedly fails to launch with the system dialog: "Can't open this app — You'll need to go to advanced options for Claude and select Repair."

Repair temporarily resolves it. The issue comes back. No official fix exists as of July 28, 2026. Multiple prior reports have been closed as "not planned" or left unresolved. This report is being filed because the pattern continues and the workaround creates a data loss risk for Cowork users. This issue has been reported in #55465, #50285, #48437, #80444, #81836, #82967 — all closed without a permanent fix. I am checking this box to indicate I am aware of those reports and filing this as a pattern escalation, not a duplicate.

What Should Happen?

Expected Behavior

App launches reliably every time.

Actual Behavior

App fails to launch intermittently. The Windows "Can't open this app" dialog appears. Repair works temporarily but the issue returns.

Error Messages/Logs

"Can't open this app — You'll need to go to advanced options for Claude and  select Repair."

Steps to Reproduce

1. Use Claude Desktop on Windows (MSIX packaged app) regularly
2. Close the app window (note: background processes remain resident in system

tray after window close)

1. On a subsequent launch attempt, the Windows system dialog appears:

"Can't open this app"

1. Repair (Settings → Apps → Advanced Options → Repair) temporarily fixes it
2. Issue recurs across future sessions without a clear trigger

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Issue started on 8/30/26

Claude Code Version

N/A — not using Claude Code CLI

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Root Cause (as documented in public GitHub issues and community research)

Claude Desktop stays resident in the system tray after the window is closed. Background processes continue running. When a package update occurs, those resident processes hold the MSIX package files open, blocking de-registration
of the old package and re-registration of the new one. The result is a half-registered package state — the registration exists but the execution entry point is gone.

This is documented behavior: GitHub #80444 recorded the GPU process dying with exitCode 101457950 (0x060C201E), after which the package state became appxState=2 (Modified) and launching was refused. In #82967, the state escalated to "Modified, NeedsRemediation" and Repair itself failed — requiring a full reinstall.

Why This Matters Beyond Inconvenience: Cowork Data Risk

The dialog steers users toward Reset and Reinstall as escalation paths. For Cowork users, this is a real problem:

• Reset permanently deletes all Cowork session history, unsaved session outputs, and locally stored user-created skills
• The Reset confirmation dialog only says it will delete "settings, cache, and login information" — it does not mention Cowork data destruction (documented in #65695)
• Cowork data does not sync to claude.ai and is not recoverable after Reset
• Reinstall loses the session list index, even though underlying files survive on disk (documented in #81907)

Every time this launch failure recurs, it puts Cowork users at risk of data loss if they follow the dialog's own instructions.

Note: claude.ai conversation history (server-side) and Claude Code sessions (%USERPROFILE%\.claude\projects\) are NOT affected by Repair, Reset, or Reinstall. The data loss risk is specific to Cowork.