Website broken after PHP upgrade

First, don’t panic

A site that breaks after a PHP change has usually not lost anything. Your pages, products, orders and images are normally still sitting in the database and files. What has changed is the version of PHP reading them, and the older code does not agree with it.

Get back online: ask your host to switch back

The quickest fix is usually to put the site back on the PHP version it used before. Many hosts let you do this yourself in the control panel, under a setting such as Select PHP Version or MultiPHP Manager. If you are not sure, contact your host’s support and ask:

• Which PHP version was my site on before the change?
• Can you switch it back to that version for now?
• Is there a date when the old version will be removed for good?

Switching back is a short term fix. The old version gets no security fixes, so the code still needs updating.

What the white screen and errors mean

• A blank white page usually means PHP hit an error and stopped before it could show anything. On PHP 8 many problems that used to be small warnings now stop the page like this
• “500 Internal Server Error” is the server’s general way of saying something went wrong while building the page
• “There has been a critical error on this website” is the WordPress version of the same message, and WordPress usually emails the site administrator more details

Copy down any error messages, or take a screenshot. They help us find the cause faster, and you don’t need to understand them.

Things to check, and things to avoid

• If only part of the site is broken, note which part: a form, the checkout, the admin area. A home page can look fine while those fail
• If a page still shows an old error after a fix, a cache may be holding on to it. Your host or a caching plugin can clear it
• Don’t start deleting plugins on the live site. It can lose settings and make the real cause harder to find
• If odd dates or missing menu items appear, the new PHP version may have different server settings (timezone, max_input_vars) from the old one

Then we fix it properly

We take a full backup, copy the site to a private staging area running a currently supported PHP version, and turn on error logging to find every place where the code or a plugin fails. We fix those, then test the forms, emails, logins and checkout that matter to your business before planning the switch with you. Your design and content stay the same wherever technically feasible.