Codex Desktop Windows: cannot start chat — invalid transport in mcp_servers.codex_app

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

26.911.61220

What subscription do you have?

ChatGPT Business

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

Codex Desktop cannot start any local chat on native Windows.

Exact error:
failed to load configuration: invalid transport in mcp_servers.codex_app

The failure occurs before the chat starts and before any command can run.

Diagnostic logs repeatedly show:
failureReason=invalid_config
method=thread/start
failed to load configuration: invalid transport in mcp_servers.codex_app

codex-cli version: 0.155.0-alpha.2.6

I checked ~/.codex/config.toml and there is no [mcp_servers.codex_app] section. No explicit WSL configuration was found. Codex is running natively on Windows.

Repairing/reinstalling Codex Workspace dependencies and checking for application updates did not resolve the issue.

What steps can reproduce the bug?

Feedback ID: no-active-thread-01a0b224-2c51-7791-b8fa-7f063a95ca4f

What is the expected behavior?

Codex should successfully start the local chat/thread and execute the requested commands in the selected local repository without a configuration error.

Additional information

The issue has reproduced repeatedly across multiple attempts.

Codex Desktop version: 26.911.61220
codex-cli version: 0.155.0-alpha.2.6
Subscription: ChatGPT Business
Environment: native Windows, not WSL.

The user config.toml does not contain an [mcp_servers.codex_app] entry, but the error references mcp_servers.codex_app during thread/start.

No project files are modified because the failure occurs before the thread starts.

Start by reproducing the native Windows startup failure and tracing configuration loading during thread/start, especially the unexpected mcp_servers.codex_app entry. Compare the loaded configuration with ~/.codex/config.toml, which lacks that section. Done means Codex Desktop starts a local chat and executes commands without the invalid-transport error.