WordPress powers a huge share of the world's websites, from one-page portfolios to busy online shops. It's flexible, popular and, most of the time, reliable.
But if you've run a WordPress site for any length of time, you've probably hit a moment where something suddenly stops working. The page goes blank, an error message appears, or the site slows to a crawl for no obvious reason.
The good news is that most WordPress problems aren't random. They nearly always have a clear cause. In this guide, we'll walk through the most common WordPress issues, explain what each one looks like, and cover what typically causes it.
1. The White Screen of Death
What it is: You visit your website and see nothing but a completely blank white page. There's no error message and no content. Sometimes it affects the whole site; sometimes only the admin area or a single page.
What causes it: The most common culprit is a faulty or incompatible plugin, often right after an update. A broken theme file can cause the same thing. It can also happen when your site runs out of the memory (PHP memory limit) your hosting allows, so WordPress simply stops loading.
2. Error Establishing a Database Connection
What it is: Instead of your website, visitors see a plain message saying WordPress can't connect to the database. Every page is affected, because your posts, pages and settings all live in that database.
What causes it: Usually the login details WordPress uses to reach the database are wrong, which often happens after a website migration or a hosting change. It can also mean the database server itself is down or overloaded, or that the database has become corrupted.
3. 500 Internal Server Error
What it is: A generic error telling you something has gone wrong on the server, without saying what. It's one of the most frustrating errors because the message gives so little away.
What causes it: Common causes include a corrupted .htaccess file, a plugin or theme conflict, an exhausted PHP memory limit, or incorrect file permissions. Sometimes it's an issue on the hosting provider's side rather than your site.
4. A Painfully Slow Website
What it is: Pages take several seconds to load, the admin dashboard drags, and visitors leave before the site even appears. Slow sites also tend to rank lower on Google.
What causes it: Large, uncompressed images are a frequent cause. So are too many plugins, especially heavy or poorly coded ones. Missing caching, a bloated database, an outdated PHP version, or simply underpowered hosting can all add to the problem.
5. Locked Out of the WordPress Dashboard
What it is: You can't log in to wp-admin. The password reset email never arrives, the login page keeps refreshing and sending you back, or you're told your account has been locked.
What causes it: Login loops are often caused by browser cookie or cache problems, or a mismatch in the site's URL settings. Security plugins can lock you out after too many failed attempts. Missing reset emails usually point to email delivery problems on the site.
6. "Briefly Unavailable for Scheduled Maintenance"
What it is: Your site shows a message saying it's briefly unavailable for maintenance, but the message never goes away.
What causes it: WordPress puts your site into maintenance mode while it installs updates. If an update is interrupted, for example by a timeout or by closing the browser mid-update, WordPress can get stuck in that mode.
7. Broken Layout After an Update
What it is: After updating WordPress, a theme or a plugin, your pages suddenly look wrong. Menus are out of place, styling has disappeared, or sections overlap.
What causes it: The update has introduced a change that your theme or another plugin isn't compatible with yet. Custom changes made directly to theme files can also be overwritten by a theme update. Leftover cached files can make the problem look worse than it is.
8. Plugin and Theme Conflicts
What it is: A feature stops working, a form won't submit, or an error appears, often only on certain pages. This isn't a single error message but a root cause behind many of the problems above.
What causes it: Plugins and themes are written by different developers. When two of them try to do similar jobs, load clashing code, or haven't kept up with the latest version of WordPress, they can interfere with each other.
9. 404 Errors on Pages That Exist
What it is: Your homepage loads fine, but clicking through to a post or page shows a "404 Not Found" error, even though the content is still there in your dashboard.
What causes it: This usually comes down to your permalink settings, the rules that control your page addresses. A damaged .htaccess file, a migration, or a plugin changing how URLs work can all break those rules.
10. "Not Secure" Warnings and SSL Problems
What it is: The browser shows "Not Secure" next to your address, the padlock is missing, or visitors see a full-page warning before they reach your site.
What causes it: The SSL certificate may have expired or not been installed correctly. Often the certificate is fine, but some images or scripts still load over plain "http", which is known as mixed content. Redirect settings that send visitors in a loop can also cause "too many redirects" errors.
11. A Hacked or Infected Website
What it is: Your site redirects visitors to strange websites, shows content you didn't add, gets flagged by Google, or your host suspends it for suspicious activity.
What causes it: Most WordPress hacks come through outdated plugins, themes or WordPress itself, where known security holes haven't been patched. Weak passwords, abandoned plugins and nulled (pirated) themes are other common entry points.
WordPress Problems Have Causes, and Causes Have Fixes
As you can see, most WordPress issues trace back to a handful of root causes: plugins and themes that don't play nicely together, updates that didn't finish cleanly, server limits, configuration settings and security gaps.
Knowing the cause is the first step. Tracking down exactly which plugin, file or setting is responsible, and fixing it without breaking anything else, is where it can get tricky and time-consuming.
Site down or acting up, and no time to dig into it? That's exactly what we do. Domohelp diagnoses and fixes WordPress problems remotely, so you can get back to running your business. Get in touch with Domohelp and we'll take a look.