Many publishers and developers have been reporting that updating to WordPress 6.4 triggered a fatal error, bringing their websites down. A search for solutions began and within hours developers discovered a bug in the page builder they all used.

Sites Crashing After Updating To 6.4

One of the first reports happened not long after WordPress 6.4, codenamed Shirley, was released.

A post in the private Dynamic WordPress Facebook group alerted members that their WordPress site crashed after updating.

One of the first clues to the problem was that all the crashed sites had the Oxygen page builder installed.

But that wasn’t the only thing users of the Oxygen page builder had in common.

SEO strategist and WordPress developer Brenda Malone (LinkedIn profile) shared that having legacy versions of the default theme, whether they’re installed or not, also caused Oxygen-based sites to crash.

Default themes are the ones that are named like Twenty Twenty One and Twenty Twenty Two.

Even though the old legacy default themes were deactivated, something about their presence while the Oxygen page builder was installed caused the site to crash.

Brenda Malone shared her observation with me:

“It apparently only happens if Oxygen is installed.”

The person who started the discussion in the private group related that he deleted all the older versions of the default theme and the site was restored.

Strange, right?

A solution proposed in the official Oxygen page builder User Group was to activate recovery mode, delete all old legacy themes then install a copy of the newest default theme, Twenty Twenty Four.

Why Did Updating WordPress 6.4 Cause Sites To Crash?

Someone in that Oxygen user group discovered and offered their theory that any active theme was loading their default style CSS, which was could be responsible for the issues.

He related that he deleted the CSS on their “oxygen bare minimum” theme and the problem went away.

As admin in the official Oxygen Facebook group posted that they are looking into what is causing Oxygen sites to crash.

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