Windows ChatGPT Work: “Could not use this project for a local chat” — project context sync repeatedly fails at filesystem stage

Environment

Windows 11
ChatGPT Windows desktop app
Package: OpenAI.Codex_26.825.6671.0_x64__2p2nqsd0c76g0
Feature: Work / local chat inside an existing ChatGPT Project
Project contains 23 source files

Problem

I can no longer start a new local Work chat inside an existing ChatGPT Project.

As soon as I try to use Work with the project selected, the UI shows:

Could not use this project for a local chat

This happens before a new Work conversation can be started. Changing the Work model does not appear relevant; the failure occurs during project-context preparation.

Relevant log evidence

The desktop log repeatedly records:

ChatGPT project context sync failed fileOrdinal=null projectSaveCount=0 ... sourceCount=23 stage=filesystem status=null syncFileCount=23

The same failure occurs repeatedly across separate attempts.

Other relevant entries show:

Local app-server project migration completed projectCount=1

and, separately:

Thread catalog sync failed errorMessage="App server account changed"

However, the app server itself remains functional enough to start a thread. The log subsequently contains a successful thread/start, followed by MCP startup with status=ready, and then another:

ChatGPT project context sync failed ... stage=filesystem

This suggests that the failure is specifically in filesystem synchronization of ChatGPT Project context rather than basic thread or MCP startup.

Troubleshooting already performed

Completely exited and restarted ChatGPT.
Force-terminated the ChatGPT/Codex process tree and restarted the application.
Previously discovered that a Python process had its working directory inside the local ChatGPT project mirror. That process was terminated.
Verified afterward with Windows Resource Monitor that there were no remaining handles matching the affected project directory.
Retried from a clean ChatGPT startup without reopening the previously stuck Work conversations.
The error persisted immediately when attempting to create a new Work chat.
Inspected the local project mirror under %USERPROFILE%.codex.chatgpt-projects. The project directory exists.
Inspected the corresponding .metadata entry. It appears to be a normal version-1 source-file manifest rather than an obvious lock/thread-state file.

Observed result

Every attempt to start a new Work/local chat with this ChatGPT Project fails with:

Could not use this project for a local chat

The desktop log records stage=filesystem, with all 23 sources counted (sourceCount=23, syncFileCount=23) but projectSaveCount=0.

Expected result

Work should create a new local chat using the existing ChatGPT Project context.

Important data-safety concern

The local project mirror currently also contains important working files, so I have deliberately NOT deleted, renamed, or manually reconstructed the .codex\chatgpt-projects project directory as a troubleshooting measure.

I would appreciate guidance on whether this is a known Windows project-context synchronization issue and, if so, whether there is a safe way to reset the local Work/project binding without deleting or damaging the project mirror.

I can provide the relevant desktop log and screenshots if needed.

Reproduce a new Work/local chat with the existing project, then inspect the desktop log entries for stage=filesystem, sourceCount=23, syncFileCount=23, and projectSaveCount=0. Review the local mirror and its .metadata entry under %USERPROFILE%.codex.chatgpt-projects without deleting them; done means a new local chat starts successfully while preserving the project mirror.