Common causes of “There has been a critical error on this website”
Not every WordPress critical error has the same root cause. Some happen immediately after a plugin update. Others start after a theme change, a PHP version switch, a custom code snippet, a server migration, or a malware infection. That is why guessing often makes the problem worse.
In real repair work, the goal is not just to hide the error message. The goal is to understand what actually broke, restore safe access to the site, and prevent the same failure from happening again.
I focus on diagnosis first, repair second
Many site owners panic and start disabling random files or reinstalling WordPress without knowing the cause. My workflow starts with identifying whether the issue is coming from a plugin, theme, server change, PHP fatal error, custom code problem, or hacked file, then repairing it carefully.
Critical error after plugin update, theme update, or PHP version change
A large percentage of WordPress critical errors happen right after something changes. That might be a plugin update, a theme update, a WooCommerce update, a custom code edit, or a hosting-level PHP version change. In those situations, the fix is usually not random trial and error. It is controlled rollback, isolation, compatibility review, and proper repair.
I also handle no-dashboard-access cases, where the site is down and WordPress Recovery Mode is not available or the admin never received the email. Those cases usually require direct hosting-level work.