Failed to fetch cross-domain content

I believe it’s in the theme, which is a child theme of Astra, aka https://wpastra.com/

(I put the site into troubleshooting mode and with only Jetpack Boost enabled, the Critical CSS function works. When I switch from Twenty Twenty to the site’s theme, it chokes on the same URL.

I would like to take this up with the theme developers. It’s great to have a single URL to use as a starting point for troubleshooting, but is there any way to know what Jetpack Boost is choking on? What content it’s ‘failing to fetch’.

Where can I find any more detail about the error?

Hi @cmkl

It’s because that page you mentioned is redirecting to an external URL.

We’re working on a fix that will handle these errors better, but for now, you could temporarily remove any page redirects and that should allow the CCSS to be generated, at which point you can enable the redirects again.

Well the update that you rolled out in the last few days gets past the page with the external URL redirect when generating Critical CSS. The progress bar gets all the way over to the very end but then I see a red notice appear with:

An error occurred while sending Critical CSS generation results to the server: Unexpected end of JSON input

I can dismiss the notice, but I still see the ‘Generating Critical CSS’ notice above the progress bar and I get warned that Jetpack Boost is still generating critical CSS and I shouldn’t navigate away from the page.

So… progress, sort of.

Hi @cmkl

I would also recommend you to purge any caches that you might have (WordPress cache, Cloudflare cache, etc) and try logging in to your site in an incognito window (to prevent browser cache from interfering) and try it out.

If the above steps are not helping, can you take a screenshot of the DevTools Network tab and the Browser Console? Please make sure to take a screenshot when you’re on the Jetpack Boost dashboard.

Hi there,

It has been more than one week since we have heard from you, so I’m marking this topic as resolved. But If you have any further questions or need some more help, you’re welcome to reply here or open another thread.