Codex VS Code panel becomes blank after opening reasoning details

What version of the IDE extension are you using?

Extension version: 26.901.22334

What subscription do you have?

PRO

Which IDE are you using?

VS Code

What platform is your computer?

No response

What issue are you seeing?

Codex VS Code panel becomes blank after opening reasoning details

Environment

• OS: macOS
• VS Code extension: openai.chatgpt
• Extension version: 26.901.22334
• Workspace type: local workspace
• Codex panel: VS Code extension / Codex coding agent

Description

The Codex panel becomes gray/blank and appears to stop rendering when I open or inspect the reasoning/thinking area.

The Codex backend process still appears to be running, but the Webview UI becomes unusable. This seems to be a frontend rendering issue rather than an intentional restriction on displaying reasoning content.

Steps to reproduce

1. Open a local workspace in VS Code.
2. Open the Codex panel.
3. Send a request and wait for the reasoning summary to appear.
4. Open or inspect the reasoning/thinking section.
5. The Codex panel becomes gray/blank or stops rendering.

Expected behavior

The reasoning summary should render normally, or the UI should remain usable if the summary is unavailable.

Actual behavior

The Codex panel becomes blank/gray. Repeated ResizeObserver errors appear in the logs.

Relevant logs

2026-09-09 20:49:39.220 [error] Error fetching httpStatus=403 requestId=a386506b7929ec01-NRT statusText=Forbidden url=/settings/user
2026-09-09 20:49:39.221 [warning] sa_server_request_failed attachAuth=false attachIntegrityState=false error={} hasRequestBody=false method=get requestHeaderNames=["OAI-Language","User-Agent","oai-did","originator","sec-ch-ua","sec-ch-ua-mobile","sec-ch-ua-platform"] routePattern=/settings/user status=403 url=/settings/user

2026-09-09 20:49:39.965 [error] [desktop-notifications][global-error] ResizeObserver loop completed with undelivered notifications.
2026-09-09 20:49:39.991 [error] [desktop-notifications][global-error] ResizeObserver loop completed with undelivered notifications.
2026-09-09 20:49:40.013 [error] [desktop-notifications][global-error] ResizeObserver loop completed with undelivered notifications.
2026-09-09 20:49:40.041 [error] [desktop-notifications][global-error] ResizeObserver loop completed with undelivered notifications.

2026-09-09 20:49:40.170 [warning] [CodexMcpConnection] cli: message="codex_core_plugins::manifest: ignoring interface.defaultPrompt[0]: prompt must be at most 128 characters path=file:///Users/didi/.codex/.tmp/plugins/plugins/ngs-analysis/.codex-plugin/plugin.json"

2026-09-09 20:49:42.336 [info] maybe_resume_started conversationId=01a08629-ab02-7da3-9dbd-f801ad55f962 documentVisibilityState=visible hostId=local previousResumeState=resumed previousStreamRole=owner routePath=/index.html

2026-09-09 20:49:42.459 [error] Request failed conversationId=none durationMs=2 error={"code":-32603,"message":"No such file or directory (os error 2)"} failureReason=null id=a1aa1f70-1955-46a6-a7a8-e1b6b89ed728 method=fs/readDirectory pendingCountAfter=1 priority=interactive queueWaitMs=0 source=filesystem spanId=null timeoutMs=0

2026-09-09 20:49:56.441 [info] Reasoning summary item completed itemId=rs_04f33faf6379945f016aa155f37db887d09d0d611ea887701b summary=[] summaryPartCount=0 threadId=01a08629-ab02-7da3-9dbd-f801ad55f962 turnId=01a08637-8bf8-7b10-a452-75039e603aa4

### What steps can reproduce the bug?

## Codex VS Code panel becomes blank after opening reasoning details

### Environment

- OS: macOS
- VS Code extension: `openai.chatgpt`
- Extension version: `26.901.22334`
- Workspace type: local workspace
- Codex panel: VS Code extension / Codex coding agent

### Description

The Codex panel becomes gray/blank and appears to stop rendering when I open or inspect the reasoning/thinking area.

The Codex backend process still appears to be running, but the Webview UI becomes unusable. This seems to be a frontend rendering issue rather than an intentional restriction on displaying reasoning content.

### Steps to reproduce

1. Open a local workspace in VS Code.
2. Open the Codex panel.
3. Send a request and wait for the reasoning summary to appear.
4. Open or inspect the reasoning/thinking section.
5. The Codex panel becomes gray/blank or stops rendering.

### Expected behavior

The reasoning summary should render normally, or the UI should remain usable if the summary is unavailable.

### Actual behavior

The Codex panel becomes blank/gray. Repeated `ResizeObserver` errors appear in the logs.

### Relevant logs

```text
2026-09-09 20:49:39.220 [error] Error fetching httpStatus=403 requestId=a386506b7929ec01-NRT statusText=Forbidden url=/settings/user
2026-09-09 20:49:39.221 [warning] sa_server_request_failed attachAuth=false attachIntegrityState=false error={} hasRequestBody=false method=get requestHeaderNames=["OAI-Language","User-Agent","oai-did","originator","sec-ch-ua","sec-ch-ua-mobile","sec-ch-ua-platform"] routePattern=/settings/user status=403 url=/settings/user

2026-09-09 20:49:39.965 [error] [desktop-notifications][global-error] ResizeObserver loop completed with undelivered notifications.
2026-09-09 20:49:39.991 [error] [desktop-notifications][global-error] ResizeObserver loop completed with undelivered notifications.
2026-09-09 20:49:40.013 [error] [desktop-notifications][global-error] ResizeObserver loop completed with undelivered notifications.
2026-09-09 20:49:40.041 [error] [desktop-notifications][global-error] ResizeObserver loop completed with undelivered notifications.

2026-09-09 20:49:40.170 [warning] [CodexMcpConnection] cli: message="codex_core_plugins::manifest: ignoring interface.defaultPrompt[0]: prompt must be at most 128 characters path=file:///Users/didi/.codex/.tmp/plugins/plugins/ngs-analysis/.codex-plugin/plugin.json"

2026-09-09 20:49:42.336 [info] maybe_resume_started conversationId=01a08629-ab02-7da3-9dbd-f801ad55f962 documentVisibilityState=visible hostId=local previousResumeState=resumed previousStreamRole=owner routePath=/index.html

2026-09-09 20:49:42.459 [error] Request failed conversationId=none durationMs=2 error={"code":-32603,"message":"No such file or directory (os error 2)"} failureReason=null id=a1aa1f70-1955-46a6-a7a8-e1b6b89ed728 method=fs/readDirectory pendingCountAfter=1 priority=interactive queueWaitMs=0 source=filesystem spanId=null timeoutMs=0

2026-09-09 20:49:56.441 [info] Reasoning summary item completed itemId=rs_04f33faf6379945f016aa155f37db887d09d0d611ea887701b summary=[] summaryPartCount=0 threadId=01a08629-ab02-7da3-9dbd-f801ad55f962 turnId=01a08637-8bf8-7b10-a452-75039e603aa4

### What is the expected behavior?

_No response_

### Additional information

_No response_

Start by reproducing the blank Codex VS Code panel when opening reasoning details, then inspect the panel's webview rendering path and the ResizeObserver errors shown in the issue logs. The fix is complete when reasoning details no longer leave the panel gray or unusable and the normal panel remains rendered.