---
title: Critical error message on most pages
description: "Your WordPress site shows **There has been a critical error on this website** and most pages are broken, but the home page seems to load. **Why this…"
url: "https://homerunner.io/docs/my-wordpress-site-is-showing-there-has-been-a-critical-error-on-this-website-and/"
updated: "2026-10-27"
category: General
---

# Critical error message on most pages

Your WordPress site shows **There has been a critical error on this website** and most pages are broken, but the home page seems to load.

**Why this happens.** This error is caused by a known bug in certain versions of PHP. A compiler optimization feature called JIT (Just-In-Time compilation) produces a defective instruction that attempts to allocate roughly 4 gigabytes of memory in a single operation, which immediately crashes the page. The home page may appear to load because it is served from a cached copy, while all non-cached pages fail immediately. This is not caused by your content, any recent changes to your site, or your plugins.

**How it is resolved.** The fix is a change to the PHP configuration on the server that disables this faulty optimization. Once it is disabled, your site returns to normal with no data or content affected.