When WordPress stops working, the first thing to do is understand what kind of error you are seeing. A white screen, a 500 error, an unreachable database, a 403 or images that will not load all have very different causes.
This guide covers five common problems and helps you work out where to start without making random changes.
1. White screen or fatal error
If the site shows a blank page or a fatal error message, the usual causes are an incompatible plugin, the theme or a PHP problem.
- Check whether WordPress has emailed you the Recovery Mode link.
- If you cannot reach the back end, deactivate the suspect plugin via SFTP or the File Manager.
- Read the PHP logs before reactivating everything.
If the problem started right after a plugin, you will find a more complete procedure in WordPress plugin crash: how to restore your site.
2. 500 error – Internal Server Error
The 500 error is generic: it means the server could not complete the request. It can be caused by PHP, plugins, server rules, permissions or wrong configuration.
- check the server logs;
- check plugins and theme;
- look for recent changes to
.htaccess; - if necessary, regenerate the permalinks after saving a copy of any custom rules.
3. Database connection error
The message “Error establishing a database connection” means WordPress cannot communicate properly with MySQL/MariaDB.
- check the database name, user, password and host in
wp-config.php; - check that the database can be reached;
- look for problems or limits on the hosting side.
Avoid touching the database until you know whether the problem lies in the credentials or in the server.
4. 403 error – Forbidden
A 403 means the server received the request but does not allow access. Causes include wrong permissions, security rules, firewalls, plugins or server configuration.
- check whether the problem affects a single URL or the whole site;
- look for blocks by the security plugin or the WAF;
- check file and folder permissions only if you know which values are correct for your hosting;
- read the logs instead of changing permissions indiscriminately.
5. The homepage works but other pages return 404
If the homepage works but every other URL returns a 404, the problem often lies in the permalinks or the rewrite rules.
In this case try saving Settings → Permalinks again. If that is not enough, there is a dedicated guide on a working homepage with WordPress pages returning 404.
Before trying things: look at what changed
Good troubleshooting almost always starts with the same question: what changed just before the problem?
- a plugin or theme update;
- a migration;
- a PHP version change;
- a DNS or SSL change;
- new cache or security rules;
- changes to the database or files.
If the site is in production and the cause is unclear, it is better to collect logs and information before restoring a backup or mass-deactivating plugins.
For persistent technical problems, see also the WordPress maintenance and support page or contact me.