wellmadedigital

Have you tried looking at the ‘text’ tab in your WYSWYIG editor for that page in WordPress (instead of the ‘visual’ tab)? My experience is that usually there’s some styling code that’s carried over when you cut and paste from YouTube (or other video embedded code sources) that’s messing the iFrame up. AMP validation is more sensitive to these things.

Check for things like " in the embed code, etc.

Thanks for the rapid response, @jsmoriss!

Your first answer was spot on: it was the Meta Property containers option that was causing the AMP validation error when working in conjunction with https://www.ads-software.com/plugins/accelerated-mobile-pages/. Deactivating it looks like it worked, and our AMP pages are returning as valid again.

For folks that already have existing clients that won’t want to use a new editor — or worse, have sites that depend on a custom editing experience built with ACF Pro — that’s not a useful answer, Samuel Wood.