Built-in Image Generation Consistently Returns a Network Error in the Codex Windows App

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

26.707.31428

What subscription do you have?

plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

I am unable to use the built-in image generation feature in the Codex/ChatGPT Windows desktop app. The issue appears to have started after the Codex and ChatGPT desktop app integration released around July 9, 2026.
Both new image generation and reference-image editing fail with a network error.
Error when generating a new image:
image generation failed: network error: error sending request for url
(https://chatgpt.com/backend-api/codex/images/generations)
Error endpoint when reference images are used:
https://chatgpt.com/backend-api/codex/images/edits
Troubleshooting already performed:
Completely uninstalled and reinstalled the Windows desktop app.
Fully exited the app, including its system tray process, and restarted it.
Confirmed that sufficient usage capacity is available.
Tested a minimal prompt without reference images.
Re-encoded and compressed the reference images before retrying.
Checked local DNS, network connectivity, TLS, and certificate handling.
Diagnostic findings:
A minimal request without reference images still fails, so the problem does not appear to be caused by the prompt, image size, or reference-image format.
Both the system certificate store and the active custom CA bundle can reach the same image endpoint and receive the expected unauthenticated HTTP 403 response. This indicates that DNS, TCP, and TLS connectivity are working.
Normal Codex conversations and Responses WebSocket connections work correctly.
The failure appears limited to the built-in image generation extension.
The installed Windows app package version is 26.707.3748.0.
The locally installed runtime and skill bundle appear newer than the desktop host, suggesting a possible host-version or image-extension compatibility issue.
Although the app reports a generic network error, the evidence suggests that the underlying issue may involve ChatGPT authentication, account entitlement or usage mapping, or compatibility with the image generation extension.

What steps can reproduce the bug?

Steps to reproduce:
Open Codex in the Windows desktop app.
Start a new task.
Enter a simple prompt such as:
Generate an illustration of a blue butterfly under moonlight. Do not use any reference images.
Invoke the built-in image generation feature.
Wait for the request to complete.
The request fails at /backend-api/codex/images/generations with a network error.

What is the expected behavior?

Error when generating a new image:
image generation failed: network error: error sending request for url
(https://chatgpt.com/backend-api/codex/images/generations)
Error endpoint when reference images are used:
https://chatgpt.com/backend-api/codex/images/edits

Additional information

Environment:
Operating system: Windows
Desktop app version: 26.707.3748.0
Approximate occurrence time: July 11, 2026, UTC+8
Authentication method: ChatGPT account

Could you please investigate the following?
Whether the account is correctly entitled to use built-in gpt-image-2 generation in Codex.
Whether the /backend-api/codex/images/generations and /edits endpoints correctly receive and recognize the desktop app’s ChatGPT authentication token.
Whether version 26.707.3748.0 has a known compatibility issue with the image generation extension.
Whether the Windows app has received the latest build associated with the July 9 desktop integration.
Whether the app can expose the actual HTTP status or authentication error instead of presenting every failure as a generic network error.