My section won’t save, “Invalid JSON in tag schema”. Can you fix it?

Yes. The {% schema %} block at the bottom of a section must be strict JSON. A trailing comma, a duplicate setting id, a smart quote pasted from a doc, or a missing bracket all trigger Invalid JSON in tag ‘schema’ and the theme editor refuses to save. We repair the JSON, de-duplicate setting IDs, and validate the whole block so the section saves and the editor controls work again.