611c10176a27.Quick answer
Do not begin with another reinstall. Name the visible symptom, restore the external theme, and confirm that stock Codex opens. Then verify the official process, loopback port, renderer target, and current upstream version before applying the theme once more.
Classify the failure before changing files
A completely absent theme, background-only theme, missing sidebar, dead composer, and launch failure are different problems. Note whether Codex opened, whether the injection process is running, and whether the verifier found the expected official renderer. Avoid deleting state until you know which layer failed.
Check the smallest trustworthy signals
Confirm that you used the original upstream repository, the expected platform guide, and a theme directory containing a valid theme.json where required. Check that the loopback port belongs to the current official Codex process and that another local service did not occupy an explicitly requested port.
Prefer restore over escalating mutations
If verification fails or native controls stop working, restore first. Reopen stock Codex, then update or reinstall the theme engine from a pinned upstream commit. Do not disable signature checks, take ownership of WindowsApps, replace app.asar, or run a repackaged installer to force the visual layer.
Completion checklist
- Symptom is named
- Official app opens stock
- Original upstream is used
- Restore works
Frequently asked questions
Why is my Codex theme not working?
The theme launcher may not have started, the payload may have been rejected, the CDP target may not match the current official process, or a Codex update may have changed the expected renderer structure.
What if only the wallpaper loads?
Treat a background-only result as a partial failure. Record the Codex version and route, then use the post-update guide because selector or route reinjection drift is more likely than an image problem.
When should I restore the default theme?
Restore whenever native controls become unclickable, the target identity is ambiguous, verification fails, or stock Codex has not yet been proven healthy.