Structured data is present but not parsed

The JSON-LD block appears in the page source but a validator finds nothing — usually because it is injected by JavaScript, or because the JSON is malformed (a trailing comma from a template).

How to confirm it

Run this against your own domain:

curl -sS https://example.com/ | python3 -c "import sys,re,json;[json.loads(b) for b in re.findall(r'<script type=\"application/ld\+json\">(.*?)</script>', sys.stdin.read(), re.S)];print('parses')"

How to fix it

Emit the block in the server-rendered HTML, keep it valid JSON, use the type that matches the page, and connect the page node to the site entity with isPartOf/publisher.

Where it fits

This is a symptom of a failed check — here it points at B2. The failure it belongs to is only one of fifteen; the full list is in the standard, and the fix order that avoids redoing work is in the repair guide.