Windows: Codex dependencies runtime 26.915.20218 fails to install due to SHA-256 checksum mismatch

What version of the Codex App are you using?

Codex Desktop on Windows, Microsoft Store package OpenAI.Codex_26.915.4065.0_x64__2p2nqsd0c76g0.

The desktop logs report client version 26.915.31945 and bundled Codex Core/app-server version 0.155.0-alpha.9.2.

What platform is your computer?

Windows 11 x64.

What issue are you seeing?

Settings reports that Codex dependencies could not be installed/reinstalled.

The failure is not caused by a project dependency. Codex is trying to install its own primary runtime bundle:

codex-primary-runtime-win32-x64-26.915.20218.tar.gz

The download completes, but Codex rejects it during checksum verification.

Observed log event:

errorCategory=checksum_mismatch
failureStage=verify_checksum
bundleVersion=26.915.20218
target=win32-x64

The expected SHA-256 is:

06266088a7881b8fdc31adaf070e1db070ce4162e8c6137b212334b249d2e9c3

but the downloaded archive hashes to:

5911799885cacb45d0f95b1f1ed708cca2f5e5664d83291a95bf53643c18c368

The runtime URL in the log is:

https://persistent.oaistatic.com/codex-primary-runtime/alpha/26.915.20218/codex-primary-runtime-win32-x64-26.915.20218.tar.gz

The exact error is:

Checksum mismatch for 'https://persistent.oaistatic.com/codex-primary-runtime/alpha/26.915.20218/codex-primary-runtime-win32-x64-26.915.20218.tar.gz':
expected 06266088a7881b8fdc31adaf070e1db070ce4162e8c6137b212334b249d2e9c3,
got 5911799885cacb45d0f95b1f1ed708cca2f5e5664d83291a95bf53643c18c368.

This happened twice: once from the automatic startup installation (trigger=startup_missing) and again after manually choosing Repair/Reinstall (trigger=repair). Both attempts returned the same unexpected SHA-256.

What steps can reproduce the bug?

1. Run Codex Desktop on Windows x64.
2. Open Settings → Codex dependencies.
3. Attempt to install or reinstall the Codex dependencies.
4. The download runs for roughly a minute and fails.
5. Inspect the desktop log under the Codex MSIX LocalCache Logs directory.
6. The installer reports errorCategory=checksum_mismatch and failureStage=verify_checksum for runtime 26.915.20218.

What is the expected behavior?

The Windows primary runtime archive served by the CDN should match the SHA-256 digest in the runtime manifest so Codex can install the dependency bundle successfully.

Additional information

The previously installed primary runtime is still healthy:

bundleVersion=26.909.12148
installed=true
problemCount=0

Codex's own dependency diagnostics validate both bundled executables successfully:

Node:   v24.19.0 — passed
Python: 3.12.14 — passed
primary_runtime_validation_finished outcome=passed problemCount=0

Because two separate download attempts produced the same unexpected hash, this appears more consistent with an artifact/manifest publishing mismatch than a one-off corrupted local download.

No existing issue matching the exact 26.915.20218 Windows checksum mismatch was found before filing this report.

Start by comparing the served codex-primary-runtime-win32-x64-26.915.20218.tar.gz archive with the expected SHA-256 in the runtime manifest, using the Windows download URL and log details provided. Done means the CDN artifact and manifest agree and Codex Desktop can install or reinstall the dependency bundle successfully.