yes , alot of disable → restart and enable extension to make it works
I have the same issue with vscode in ubuntu 24.04
Finally find a way to make it work. Here is what I’ve done:
- Close VSCode and Codex APP, and kill all codex related threads in Windows task manager.
- remove the .codex folder in your User Folder.
- IMPORTANT: Start Codex APP and login again. It will re-create the .codex folder. DO NOT start VSCode.
- Start VSCode, then it works.
Original Post:
Still have this issue in Windows 11.
Tried everything, nothing works unless downgrade to the version last week. But I want to use GPT 5.5.
These are outputs in Codex channel:
2026-04-29 10:24:46.376 [info] Activating Codex extension
2026-04-29 10:24:46.376 [info] [CodexMcpConnection] Spawning codex app-server
2026-04-29 10:24:46.376 [error] [CodexMcpConnection] Codex process fatal error errorMessage=“Codex process errored: Failed to start Codex process: spawn UNKNOWN” exitCode=null signal=null
2026-04-29 10:24:46.376 [error] spawn UNKNOWN
2026-04-29 10:24:46.376 [error] [CodexWebviewProvider] Fatal error message=“Codex process errored: Failed to start Codex process: spawn UNKNOWN”
2026-04-29 10:24:46.376 [warning] [CodexMcpConnection] Attempted to send app-server message but stdin is destroyed message={“id”:“codex.chatSessionProvider:0”,“method”:“thread/list”,“params”:{“limit”:50,“cursor”:null,“sortKey”:“created_at”,“modelProviders”:null,“archived”:false,“sourceKinds”:[]}}
2026-04-29 10:24:46.377 [error] [CodexMcpConnection] Codex process fatal error errorMessage=“Codex process errored: Codex process is not available” exitCode=null signal=null
2026-04-29 10:24:46.377 [error] [CodexWebviewProvider] Fatal error message=“Codex process errored: Codex process is not available”
2026-04-29 10:24:46.377 [warning] [IpcClient] Received broadcast but no handler is configured method=thread-stream-state-changed
2026-04-29 10:24:46.377 [warning] [IpcClient] Received broadcast but no handler is configured method=client-status-changed
2026-04-29 10:24:46.377 [warning] [IpcClient] Received broadcast but no handler is configured method=thread-stream-state-changed
2026-04-29 10:24:46.788 [info] [wsl] eligible distro list listResult=“docker-desktop-data\ndocker-desktop”
2026-04-29 10:24:46.793 [warning] [CodexMcpConnection] Attempted to send app-server message but stdin is destroyed message={“id”:“CodexWebviewProvider.webview:5627e812-4df7-4386-98e1-e54346bfb364”,“method”:“account/read”,“params”:{“refreshToken”:false}}
2026-04-29 10:24:46.793 [error] [CodexMcpConnection] Codex process fatal error errorMessage=“Codex process errored: Codex process is not available” exitCode=null signal=null
2026-04-29 10:24:46.793 [error] [CodexWebviewProvider] Fatal error message=“Codex process errored: Codex process is not available”
2026-04-29 10:24:46.797 [warning] [CodexMcpConnection] Attempted to send app-server message but stdin is destroyed message={“id”:“CodexWebviewProvider.webview:7d24702e-c064-4b51-a5c3-4aab6e280d89”,“method”:“thread/list”,“params”:{“limit”:50,“cursor”:null,“sortKey”:“updated_at”,“modelProviders”:null,“archived”:false,“sourceKinds”:[]}}
2026-04-29 10:24:46.798 [error] [CodexMcpConnection] Codex process fatal error errorMessage=“Codex process errored: Codex process is not available” exitCode=null signal=null
2026-04-29 10:24:46.798 [error] [CodexWebviewProvider] Fatal error message=“Codex process errored: Codex process is not available”
Before taking that step, consider renaming the folder instead (e.g., .codex_original ). Codex should recreate the directory if it is missing. This approach preserves the existing contents, which may contain valuable data.
Thank you bro 
it works!
Apologies for the inconvenience. This has caused. Seems like Karas provided a workaround that resolves this issue. If any one is still facing this issue. Please open a support request with us (support@openai.com) and share the case id/case subject here with us and our team will review the case for you. Thanks!
EDIT: I just updated to v26.5422.71525 (Pre-release version) and it fixed the issue. VS Code lists the extension Last Updated as 39 seconds ago. 
EDIT 2: Also, as of 21 seconds, v26.422.71525 (Release version) fixes the issue as well.
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I do not have the Codex app installed and I may not be able to on a work PC. Is there an accepted solution if you only have VS Code using Windows?
Guys, I found a solution! First, log out of Codex. Navigate to your .codex folder and move the session folder to a different location so you don’t lose your chat history. Next, delete the original .codex folder. Finally, open VS Code or the Codex app and log back in; it will generate a new .codex folder, and everything should work as expected!