Invalid JSON-LD Syntax
Criticalinvalid-json-ld-syntax
What it checks
JSON-LD contains syntax errors and cannot be parsed
How to fix it
Fix the JSON syntax errors in your structured data. Use a JSON validator to identify and correct the issues.
An example of the problem
{"@context": "https://schema.org", "@type": "Article", "headline": "Oops",}
More detail: https://developers.google.com/search/docs/appearance/structured-data/intro-structured-data#json-ld.