Windows task archiving fails with thread-store os error 2; completed automation tasks accumulate

What version of the Codex App are you using (From “About Codex” dialog)?

26.814.5517.0

What subscription do you have?

ChatGPT Pro 20x

What platform is your computer?

Windows: 10.0.19045.7548 x64

What issue are you seeing?

Codex Desktop for Windows cannot archive completed local tasks.

When a task is archived, the operation fails in the underlying thread store with:

failed to archive session: thread-store internal error: failed to archive thread: The system cannot find the file specified. (os error 2)

The task remains visible in the active sidebar.

This is especially damaging for recurring automations because each run creates another task. Nineteen completed runs from one daily automation accumulated in the sidebar. Adding an instruction for each automation run to archive itself does not help because the archive operation itself is broken.

Some archive calls also resolve at the tool-call transport level even though their returned content reports failure. A caller can therefore mistakenly report success unless it inspects the returned text.

Environment:

Codex Desktop for Windows
Microsoft Store package: OpenAI.Codex
Version: 26.814.5517.0

Expected behavior:

Archiving should remove a completed task from the active sidebar while preserving it in the archived-task view. If archiving fails, the operation should return a structured error that cannot be mistaken for success.

Full sanitized report:

https://github.com/phillipnhenry/chatgpt-windows-app-postmortem/blob/main/Codex-Windows-Task-Archive-Failure-20260819.md

Related earlier Windows startup/bootstrap issue:

https://github.com/openai/codex/issues/36272

What steps can reproduce the bug?

1. Open Codex Desktop on Windows.

1. Create a local Codex task or select an existing completed local task.

1. Attempt to archive the task using the app task-archive operation.

1. Refresh or inspect the active sidebar.

1. Observe that the task remains visible.

1. Retry the archive operation and inspect the returned result.

The operation fails with:

failed to archive session: thread-store internal error: failed to archive thread: The system cannot find the file specified. (os error 2)

The same problem can be reproduced with recurring automation tasks:

1. Configure a recurring automation that creates a separate task for each run.

1. Instruct the completed automation run to archive its own task.

1. Allow the automation to complete.

1. Observe that the completed run remains visible in the active sidebar.

1. Repeat the automation and observe that another completed task is added to the sidebar instead of the prior run being archived.

What is the expected behavior?

_No response_

Additional information

_No response_