[BUG] Desktop app reinstall silently loses all Claude Code session list entries — transcripts intact on disk but unrecoverable from the UI

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?

After a failed auto-update left the desktop app in a wedged MSIX state (0x80073CF6, already tracked in #49655 / #49917), a clean reinstall was the only way to get the app running again. The reinstall wiped the entire Claude Code session list in the app (31 sessions).

Every transcript was still intact under ~/.claude/projects, and claude --resume in a terminal listed all of them correctly. Only the app's index was gone. But the app offers no export, import, or rescan path, and /resume is unavailable in the app environment ("/resume isn't available in this environment").

From the UI alone this is indistinguishable from permanent data loss. I happen to be able to read the app's internals, so I reverse-engineered the session metadata format and restored all 34 entries by hand — it took about 2 hours. Most users would have concluded their work history was gone.

What Should Happen?

Reinstalling the desktop app should not orphan the Claude Code session list.

At minimum, the app should be able to rebuild its list from ~/.claude/projects, since every transcript is already there. A "Rescan sessions" action would have turned this 2-hour manual recovery into one click.

Error Messages/Logs

Installation failed: AddPackage failed: AddPackage failed with HRESULT 0x80073CF6

App launch (before reinstall):
"This app can't be opened. There is a problem with Claude. Reinstall the application from its original install location or contact your administrator."

In-app when trying to resume:
"/resume isn't available in this environment."

After reinstall, opening a restored session with a stale mapping:
"Session transcript unavailable — this session's conversation history is no longer on disk."
(no diagnostic about which path failed to resolve)

Steps to Reproduce

1. Let an auto-update run while CoworkVMService holds locks on

%LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\SystemAppData\Helium\User.dat
The update fails and leaves the MSIX package wedged (see #49655, #49917).

1. Try Settings > Apps > Advanced options > Repair, then Reset. Both fail.

1. Uninstall and run the installer again:

-> "Installation failed: AddPackage failed with HRESULT 0x80073CF6"

1. Reboot, then in an elevated PowerShell:

Stop-Service CoworkVMService -Force
Get-AppxPackage Claude | Remove-AppxPackage
Run the installer again -> succeeds.

1. Sign in and open the Code tab.

-> Session list is completely empty (31 sessions gone).
-> ~/.claude/projects/**/*.jsonl is fully intact.
-> claude --resume in a terminal lists all 31 sessions correctly.
-> No export / import / rescan option exists in the app UI.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.219

Claude Code Version

2.1.220 (claude code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Plan: Claude Max subscription (not API).

What I found while recovering

The app's session list is backed by JSON files, NOT Local Storage / IndexedDB.
I dumped both leveldb stores and found only 5 claude.ai origin keys, no session schema.

%LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\
claude-code-sessions\<accountUuid>\<workspaceUuid>\local_<uuid>.json

<accountUuid> matches lastKnownAccountUuid in the sibling config.json.

Each file maps an app session to a CLI transcript via cliSessionId, which is the
basename of the .jsonl in ~/.claude/projects. Three behaviours cost significant time:

1. The app resolves transcripts by encoding originCwd ([^a-zA-Z0-9] -> -) into

~/.claude/projects/<enc>/<cliSessionId>.jsonl. originCwd must be the cwd at
SESSION START. Using a later cwd (e.g. after a mid-session cd) silently breaks
resolution.

1. Files placed at the top level of claude-code-sessions/ are ignored. They must live

under <accountUuid>/<workspaceUuid>/.

1. If a session JSON is malformed or mis-encoded, the app opens it, fails, and DELETES

the cliSessionId key, leaving only a generic "transcript unavailable" message with
no diagnostic.

Requests

1. Add a "Rescan sessions" action that rebuilds the app list from ~/.claude/projects.

The data was never lost, only the index. This alone would eliminate the entire issue.

1. Add export/import for session metadata, including user-set titles and pinned state

(these live only in app-local data; .jsonl only carries the auto-generated ai-title).

1. Warn before uninstall that the session list will be lost, with an option to export.
2. Support /resume in the app, or explain why it differs from the CLI.
3. Surface a diagnostic when transcript resolution fails instead of silently dropping

cliSessionId.

Note

I'm not asking for compensation - everything was recovered. I'm filing this because the
failure mode looks irreversible to anyone who can't inspect the app's internals, and a
rescan button would eliminate it entirely.