A JSON-LD for SEO customer emailed me with a problem they were having with Google Search Console and blocked pages.
Hi I need your help big time please 266 pages have come backed blocked from Google
Those blocked resources aren't a problem, that's actually what you want.
The /cart.js url is blocked by Shopify because that is the code that runs when someone adds a product to their cart.
Shopify blocks it because they don't want Google or other search engines to use that url, otherwise they'd be adding products to carts and clearing out your inventory.
What usually happens is that your theme references the /cart.js url on the product page, which is getting detected by Google. In this case, it's on 266 product pages which is why there are 266 errors reported.
It's a core part of Shopify and your theme. So even though Google Search Console considers an error, you can just ignore it.
Though I can't promise any results with it, after seeing the additional traffic and sales some customers are getting, installing JSON-LD for SEO might be one of the highest ROI decisions you make today.