Codex App fails to start on Windows after reinstall due to stale marketplace entries in config.toml

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

Latest version from Microsoft Store (2026-06-08)

What subscription do you have?

ChatGPT Free

What platform is your computer?

Windows 11 x64

What issue are you seeing?

After installing Codex from the Microsoft Store, the app fails to start or throws errors.

The root cause is a stale config.toml file left over from a previous installation. The file contains references to a local marketplace runtime path that no longer exists on disk:

[marketplaces.openai-primary-runtime]
source_type = "local"
source = '\?\C:\Users\<USER>\.cache\codex-runtimes\codex-primary-runtime\plugins\openai-primary-runtime'

[plugins."documents@openai-primary-runtime"]
enabled = true

[plugins."spreadsheets@openai-primary-runtime"]
enabled = true

[plugins."presentations@openai-primary-runtime"]
enabled = true

What steps can reproduce the bug?

1. Install Codex on Windows (Microsoft Store)
2. Use it with plugins/marketplace configured
3. Uninstall Codex
4. Reinstall Codex from Microsoft Store
5. App fails to start — config.toml still has old marketplace entries pointing to missing paths

What is the expected behavior?

Codex should detect and clean up stale marketplace/plugin entries that point to non-existent paths on reinstall, or show a clear error message like "Marketplace path not found: ..." to guide the user.

Additional information

Fix: Replacing the entire config.toml at:
C:\Users\<USER>\AppData\Roaming\OpenAI\codex\config.toml

with just:

[windows]
sandbox = "unelevated"

resolved the issue immediately.

Keywords: Codex Windows reinstall crash, config.toml marketplace error, openai-primary-runtime not found, Codex Microsoft Store bug