Why it matters
Disallow: / blocks crawling entirely, which removes the site from Google, from Bing (and so Copilot and ChatGPT's search partner), and from AI answers. Usually a preview config leaking to production. This is a scoring gate.
How to fix it
Only return Disallow: / on non-production deployments (check VERCEL_ENV).
References
More seo rules
void seo reports 60 rules in this category. What search engines need from the raw response: status codes, titles and descriptions in <head>, self-referencing canonicals, one h1, crawlable links, Open Graph, icons, robots.txt and a sitemap with real dates.
theme-colorNo theme-color metarobots-txt-unreachablerobots.txt returns 5xx/429 or times outrobots-txt-missingNo robots.txtrobots-txt-invalidrobots.txt serves HTML, exceeds 500 KiB, or has unparseable linesrobots-blocks-resourcesrobots.txt blocks JS/CSS needed to renderrobots-sitemap-directiverobots.txt has no absolute Sitemap: linesitemap-missingNo reachable sitemapsitemap-invalidSitemap isn't valid sitemap XML or exceeds protocol limits