My WordPress Site Broke After a PHP Upgrade

What's happening

PHP is the programming language WordPress runs on, and your hosting company decides which version your site uses. When they upgrade it, every plugin and theme on your site has to work with the new version. Most do. One that hasn't been updated in years often doesn't, and when it fails, it can take the whole site with it: a blank white page, a critical error, a 500 error, or a page with a "Fatal error: Uncaught" message on it.

Your pages, posts, images and orders are not affected. They're stored in the database, and the PHP version has nothing to do with them. The site will show them again as soon as the thing that broke is fixed.

Why it happens

Each new PHP version drops some old ways of doing things. Code written for a version from several years ago can rely on exactly those, and it stops working the day the version changes. The usual suspects are a plugin that's no longer maintained, a theme bought years ago and never updated, custom code a previous developer added, or a very old version of WordPress itself. Hosts upgrade PHP because old versions stop getting security fixes, so putting it off isn't an option for them.

If your site shows a message with a file name in it, the file's path often names the plugin or theme at fault. That's useful to keep, even if the rest of the message means nothing to you.

What you can safely try

• Check your email from your host. The upgrade notice usually says which version you moved from and to, and whether you can switch back temporarily.
• If your hosting control panel offers a PHP version setting, switching back to the previous version usually brings the site straight back. Treat it as a pause, not a fix: the old version will be removed before long.
• Note which plugins and themes haven't been updated in a long time. The Plugins screen shows the last update date for each. Those are the likely cause.
• Don't delete plugins to find the culprit, and don't try to edit the code yourself. Deleting a plugin can wipe its settings, and a typo in a code file turns one error into another.

When to call us

This is a standard repair on business websites. We find exactly which plugin, theme or piece of custom code can't run on the new PHP version, then update it, replace it with something maintained, or fix the code, and check your key pages and forms afterwards. The site ends up on a current, supported PHP version instead of a borrowed old one. It's a flat rate you approve before any work starts. Start with our Site Down or Critical Error Fix.