WordPress 7.1 came out on 19 August 2026. If your site is built with WordPress 7.1 ACF blocks, editing it got harder overnight.

What changed

WordPress 7.1 now loads the block editor inside an iframe. Older ACF blocks (Blocks V2) can’t run their edit form inside it. ACF’s release notes put it plainly: “The iframe stays, and the libraries needed to run V2 editing are no longer available inside the canvas.”

In practice, blocks get stuck in preview mode and their fields get squeezed into the sidebar.

That’s a lot of sites. ACF has more than 2 million active installs, and WordPress runs 39.6% of all websites.

What developers are saying

ACF’s support forum filled up the day after release:

“Do not update to 7.1 if you want to keep the blocks usable…”

“Same here, all my sites are broken in the back office and can no longer be edited”

ACF released a compatibility plugin, but their own product manager called it “a temporary bridge while you plan migration, not a long-term fix”.

In short, there’s no undo button. Blocks need updating.

What we’ve done

  • Emailed all our WordPress clients each week over the past two to four weeks to keep them updated on what’s changed.
  • Held updates on affected sites until each fix had been tested on staging.
  • Built two fixes:
    • Essential fix – a clean, working edit view for every block. Around 2 hours per site, included in our maintenance packages.
    • Full visual editing – we’ve developed a custom solution so blocks can show in the editor exactly as they look on the live site, with real content. Find any word with Ctrl+F, click the block, edit it. It’s built on ACF Blocks V3, which is where ACF and WordPress are heading, so it isn’t a stopgap.
  • Spoken directly with the ACF team at WP Engine.
  • Moved all new builds to inline editing from day one.

Why it matters who looks after your site

An update is free to install. Knowing what it’ll do to your site isn’t.

Our clients didn’t have to read changelogs or forum threads. They got an email, a working editor and a choice about what came next.

Not sure if your site’s affected? Get in touch and we can take a look.