Canonical tag points to a page that is itself blocked from search results

A canonical tag tells search engines which address is the preferred, "real" version of a page. This check looks for canonical tags that point to a target page which carries a noindex instruction, a separate tag telling search engines to leave that page out of results entirely. On this site, at least one page canonicalizes to a target that is itself set to noindex. Telling Google "this other page is the real one" while also telling it "do not show that page in search results" is a contradiction. Search engines have to guess what you actually want, and the safest guess is often to drop both pages from the index, so this combination can cost you visibility on content that should be ranking. Your developer should either point the canonical tag at a different, indexable page, or remove the noindex instruction from the target page if it was meant to appear in search results. Once the pages involved are identified, this is a quick fix, usually under an hour.