[BUG] Session not found on disk for all sessions except most recent after update to 1.9659.2 (May 28)

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?

Environment:

Claude Desktop version: 1.9659.2 (390d6c), 2026-05-28T21:50:01.000Z
macOS (Apple Silicon)
Sessions stored in: ~/Library/Application Support/Claude/claude-code-sessions/

Description:
After the May 28 update, all Code sessions except the most recent one show "Session not found on disk / Send a message to start fresh in this directory." Sessions are visible in the left nav with correct titles and project names, but cannot be loaded. This worked correctly as of ~May 21.
Root cause identified:
The update migrated session storage from local-agent-mode-sessions/ to claude-code-sessions/ under ~/Library/Application Support/Claude/, but no migration ran to move existing session folders and data to the new location. Specifically:

Session metadata (.json files) exists in the new claude-code-sessions/ directory
Session folders (audit.jsonl, outputs, uploads, etc.) were not migrated
The corresponding .jsonl transcripts in ~/.claude/projects/<encoded-path>/ exist but the app still cannot load the sessions

What was tried:

Manually copying local_*.json files from local-agent-mode-sessions/ to claude-code-sessions/ — did not fix
Manually copying session folders (containing audit.jsonl, outputs, etc.) — did not fix
Confirming cwd directories exist on disk — they do
Creating missing ~/.claude/projects/<encoded-path>/ folders and stub .jsonl files — did not fix
Restoring actual .jsonl transcripts from Time Machine backup into ~/.claude/projects/ — did not fix

Impact:
All historical Code sessions are inaccessible. Session data appears intact on disk — this is a display/loading regression, not data loss. Only the single most recent session loads correctly.
Request:
A migration step that properly moves or relinks existing sessions from local-agent-mode-sessions/ to claude-code-sessions/ so historical sessions become accessible again.

What Should Happen?

Project/session/history information should display when selecting

Error Messages/Logs

"Session not found on disk."

Steps to Reproduce

Steps to reproduce:

Have an existing Claude Desktop installation with multiple Code sessions
Update to version 1.9659.2
Open Claude Desktop → Code tab
Click any session in the sidebar other than the most recent one
See "Session not found on disk"

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.144

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_