[Windows] Update to 26.825.4187.0 fails because ChatGPT-x64.msix returns 404 BlobNotFound

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

26.820.10647.0

What subscription do you have?

ChatGPT Plus

What platform is your computer?

26100.7840 x64

What issue are you seeing?

The ChatGPT/Codex Windows desktop app repeatedly detects an update from 26.820.10647.0 to 26.825.4187.0, but the update cannot be installed.

The updater attempts to download the following package:

https://persistent.oaistatic.com/codex-app-prod/releases/26.825.4187.0/ChatGPT-x64.msix

Windows AppX deployment logs show:

Event ID 404

AppX deployment operation failed with error 0x80073CF0.

Specific error:
0x80190194: Failed to open package from location ChatGPT-x64.msix.

Event ID 403

Error 0x80190194: Unable to obtain staging session for:
https://persistent.oaistatic.com/codex-app-prod/releases/26.825.4187.0/ChatGPT-x64.msix

Event ID 497

Error 0x80070002:
Failed to open Msixvc package from location ChatGPT-x64.msix.

I tested the exact package URL independently with:

curl.exe -I -L "https://persistent.oaistatic.com/codex-app-prod/releases/26.825.4187.0/ChatGPT-x64.msix"

The server responds:

HTTP/1.1 404 Not Found
Content-Type: application/xml
Server: cloudflare
x-ms-error-code: BlobNotFound
cf-cache-status: HIT

So the package referenced by the built-in updater appears to be missing from the release storage endpoint.

The currently installed package is still healthy and reports:

Name         Version        PackageFullName
OpenAI.Codex 26.820.10647.0 OpenAI.Codex_26.820.10647.0_x64__2p2nqsd0c76g0

Microsoft Store also recognizes the official ChatGPT product (9PLM9XGG6VKS), but currently does not offer a newer version:

winget upgrade --id 9PLM9XGG6VKS --source msstore --include-unknown --accept-source-agreements --accept-package-agreements

Result:

No available upgrade found.
No newer package versions are available from the configured sources.

Therefore the current state is:

Installed version:       26.820.10647.0
Updater target version:  26.825.4187.0
Updater MSIX URL:        HTTP 404 / BlobNotFound
Microsoft Store:         No newer version available

The update fails every time it is retried.

What steps can reproduce the bug?

1. Install and run the Windows Microsoft Store/MSIX version of the ChatGPT/Codex desktop app.

2. Have version 26.820.10647.0 installed.

3. Launch the app and allow the built-in updater to check for updates.

4. The updater detects version 26.825.4187.0.

5. Attempt to install the update.

6. The update fails with:

Unable to install the ChatGPT update

7. Check the Windows AppX deployment event log. It reports 0x80190194 while attempting to stage:

https://persistent.oaistatic.com/codex-app-prod/releases/26.825.4187.0/ChatGPT-x64.msix

8. The failure can also be reproduced independently of the app by requesting the package URL directly:

curl.exe -I -L "https://persistent.oaistatic.com/codex-app-prod/releases/26.825.4187.0/ChatGPT-x64.msix"

9. The endpoint returns:

HTTP/1.1 404 Not Found
x-ms-error-code: BlobNotFound

No Codex session ID, token usage, or context window is involved, since the failure occurs in the desktop application's update mechanism before any Codex session is relevant.

What is the expected behavior?

If 26.825.4187.0 is an active release, the MSIX package referenced by the built-in updater should exist and download successfully, allowing the application to update normally.

If 26.825.4187.0 has been withdrawn, has not finished publishing, or is not intended for this device/update channel, the built-in updater should not advertise it as an available update.

The updater should also avoid repeatedly attempting to install a release whose package URL returns HTTP 404.

Additional information

The exact package endpoint currently returns:

HTTP/1.1 404 Not Found
Server: cloudflare
x-ms-error-code: BlobNotFound
cf-cache-status: HIT

This suggests that the updater metadata advertising 26.825.4187.0 and the actual package available in codex-app-prod may be temporarily out of sync.

The Microsoft Store product itself appears healthy:

ChatGPT [9PLM9XGG6VKS]
Publisher: OpenAI
Installer Type: msstore

but the Store currently reports no newer package for this installation.

There are also unrelated AppX cleanup warnings concerning an old Intel Graphics Software package under:

C:\Program Files\WindowsApps\Deleted\AppUp.IntelArcSoftware_...

However, these appear unrelated to this issue because the ChatGPT MSIX release URL independently returns 404 BlobNotFound.

This looks closely related to #38758, but in this case the failing 26.825.4187.0 package URL has been directly verified to return 404 BlobNotFound.

Start by reproducing the failure with the PowerShell curl.exe request to the advertised 26.825.4187.0 ChatGPT-x64.msix URL and compare it with the updater’s release metadata. Done means the advertised package downloads and installs, or the updater no longer offers the target when the blob returns 404 and does not retry it repeatedly.