Quick answer
Fully quit Codex Desktop—not just the window—then reopen it and start a fresh conversation. One reporter confirmed the restart created a new sandbox helper directory. If it repeats, use native mode for Windows repositories or the Linux CLI inside Ubuntu for WSL repositories.
The exact error
Unable to spawn codex-linux-sandbox because it doesn't exist on the filesystem (ENOENT)Do not use this guide for a merely similar message. The workaround is scoped to this signature and the environments below.
Match your environment
- Windows 11 with WSL2
- Codex Desktop
- New or resumed tool calls
What to do
- 01
Stop retrying the same tool call
The error occurs before the requested command starts. Repeating that command cannot recreate a missing sandbox executable.
- 02
Fully exit Codex Desktop
Close the app and confirm its background process is no longer running, then reopen it. A first-hand report found this generated a fresh helper location.
- 03
Create a fresh conversation
Test a harmless command in a new chat before resuming an old thread. This separates stale conversation runtime state from a machine-wide failure.
- 04
Match the runtime to the repository
For a repository stored on Windows, use native Windows mode. For a repository inside the WSL filesystem, open Ubuntu and run the Linux Codex CLI there.
What likely happened
Codex attempted to launch a generated Linux sandbox helper from a path that no longer existed. The confirmed restart recovery suggests stale or missing runtime material, but the reports do not prove why it disappeared.
First-hand sources
Source links support the environment and workaround claims above. An issue being closed does not by itself mean a fix shipped.