[BUG] All sessions lost after Claude Desktop update on Windows (data intact on disk)

Just had the same on MacOS. Claude 1.1.9493 (b58a0b). All sessions lost and restart didn't recover them.

Session data was there in .jsonl form in my projects folder, just not human readable. Got Claude Code to write me a script to convert them to text so I could archive them for reference so I didn't lose too much work, but can't trust the app with anything major until this is fixed.

The root cause for this (and likely many other "session loss" reports) has been identified — it is the 64KB head buffer limit in the session file parser.

How it works

The VS Code extension reads only the first 64KB (D2=65536 in extension.js) and last 64KB of each .jsonl session file to extract a title/prompt. The code path is:

listSessions() → Fd() → xZ4() → Cp() → Pp()

Pp() looks for customTitle, aiTitle, lastPrompt, summary, or the first user prompt text within these two 64KB windows. If none are found, it returns null and the session is silently dropped from the sidebar.

When it triggers

When the first user message contains pasted screenshots, the base64-encoded image data makes that single JSONL line 100KB–5MB. This pushes the ai-title record (generated after the first AI response) past the 64KB head window. If the file is large enough, the ai-title also falls outside the 64KB tail window — landing in the gap between the two read windows.

Result: The session file is perfectly valid, present in sessions-index.json, and resumable via CLI — but invisible in the VS Code sidebar.

Scope

I hit this on Windows 11 / VS Code / v2.1.108: 22 out of 193 sessions were silently dropped. Every single one had screenshots in the first message. All other sessions (text-only first messages) were fine.

This same mechanism likely explains many of the open "session loss" reports (#9258, #41455, #31787) where users see their .jsonl files on disk but sessions don't appear in the sidebar.

Workaround

Inject a small ai-title record near the top of each affected .jsonl file (after the queue-operation lines, within the first 64KB):

{"type":"ai-title","aiTitle":"Session title here"}

All 22 sessions reappeared immediately after a VS Code reload. Backups recommended before modifying files.

Suggested fix

Write the ai-title record early in the .jsonl file — immediately after generating it, not buried after the (potentially huge) first user message and first assistant response. This is a small change that would permanently prevent the issue.

Previously reported in #29088 (closed as not planned) and #31813 (closed as duplicate).

try https://github.com/lacique77/claude-sidebar-restore

Lost Projects and historical conversations/threads after upgrading to PRO license.

I was using a FREE license of Claude (Claude.ai AND "Claude for Windows" desktop application.

Then, yesterday, I upgraded and paid for a PRO license for the first time and consequently, my Projects and Historical "conversations" (threads or sesions) have disappearded from the desktop app. However, they still appear on Claude.ai (cloud).

I have verified that both, the Claude.ai and the desktop "Claude for Windows" are both logged in with the same email address.

Same issue observed on a fresh install (not an update):

• OS: Windows 11 Pro 10.0.26200
• Claude Desktop 1.3109.0.0 (freshly installed today, never had a previous version)
• Symptom: sidebar shows only current session across all projects

Additional details that may help debugging:

• "See More" link is clickable; expanding reveals "Dispatch" and "Customize sidebar" options, but no past sessions listed
• claude --resume from CLI lists all sessions correctly (CLI index is healthy)
• Deleting ~/AppData/Local/Packages/Claude_*/LocalCache/Roaming/Claude/IndexedDB/ cleared the "Internal error opening backing store for indexedDB.open" log errors, but session visibility did not return
• Log shows recurring 401 "You must authenticate with GitHub" on /api/organizations/.../code/repos even after re-authentication via Customize
• Logout/login did not fix it. Full app restart did not fix it.

This suggests the bug is not limited to update migration - the core issue is that the desktop app cannot populate the session list in the sidebar, independent of whether sessions existed before or were freshly created.

Related filed issue: #50292 (I am closing as duplicate of this one).

I hit a related-but-more-specific variant of this on Windows and wanted to add a diagnostic distinction that may help other users recover data.

There are at least four different session-history failure modes with similar UI symptoms:

1. Metadata missing entirely: JSONLs exist under ~\.claude\projects\..., but %APPDATA%\Claude\claude-code-sessions\<acct>\<org>\ has no matching local_<uuid>.json. This is close to the original report here.
2. Metadata exists but lacks cliSessionId: the history picker still shows the session, but clicking it renders a blank pane because Desktop has no bridge from local_<uuid>.json to <cliSessionId>.jsonl.
3. Metadata has cliSessionId, but JSONL is gone: the metadata points at a transcript that no longer exists. This is usually unrecoverable without backup.
4. MSIX/EXDEV .tmp files: session files remain stuck as local_<uuid>.json.tmp and never commit to .json.

The quick check for variant 2 is:

Canonical write-up from this investigation: #56172

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

All projects in the Claude Windows App were gone after upgrading to Pro. WT..

To anyone that still has this issue and need a workaround for attempt recover you can also refer to https://gist.github.com/XPOL555/1003cb862a88561dfad3f843f74de68f and https://www.reddit.com/r/ClaudeCode/comments/1th38n9/comment/p0l2che/?context=1&screen_view_count=1&ext-referrer=DIRECT and https://gist.github.com/XPOL555/1003cb862a88561dfad3f843f74de68f?permalink_comment_id=6285875#gistcomment-6285875

this seems to be a frequent issue, sadly

p.s. always do a backup 🚑