The theme does not appear
Move the whole theme folder into the themes directory. Keep theme.json and its referenced background image together in that folder.
The image works, but text is hard to read
Return to the builder and adjust brightness, image focus, and the content safe area. Export the theme again. Do not hide Codex controls to make the image stand out.
It stopped working after a Codex update
Restore the regular appearance, download the latest Dream Skin from GitHub, and reinstall it. Do not copy old program files over a newer Codex version.
Still stuck
Save the exact error and relevant logs, then open a GitHub issue. Never share API keys, sign-in files, or private conversations.