Windows app keeps deleted ChatGPT conversations in sidebar

Description

The ChatGPT Windows app continues to show conversations that have already been deleted on the server. These conversations are absent from the ChatGPT web version.

Opening, deleting, or archiving one of these stale sidebar entries fails.

Steps to reproduce

1. Delete a conversation.
2. Open the ChatGPT Windows app.
3. Find the deleted conversation still present in the sidebar.
4. Try to open, delete, or archive it.

Expected behavior

When the server reports that a conversation has been deleted, the app should remove its stale entry from the sidebar.

Actual behavior

The conversation remains visible. Opening it fails, and attempting to delete or archive it produces an error notification.

Diagnostics

App package: OpenAI.Codex_26.901.6511.0_x64__2p2nqsd0c76g0

Observed on: September 6, 2026

Relevant server response:

HTTP 404
code=conversation_deleted
can_retry=false

Relevant timestamps:

2026-09-06 11:35:24–11:35:56 UTC
2026-09-06 16:35:24–16:35:56 Asia/Yekaterinburg

Signing out and back in, Windows Repair, and Windows Reset did not resolve the issue.

The problem affects only the Windows app. The deleted conversations do not appear on chatgpt.com.

Session ID: [INSERT SESSION ID HERE]

Start by locating the Windows app's sidebar conversation state and handling for the server response code conversation_deleted with HTTP 404. Reproduce the stale-entry case and trace what happens when opening, deleting, or archiving it. Done means deleted conversations disappear from the sidebar and those actions no longer produce error notifications.