The 8 most common WordPress errors: what they mean and what to do

You open your website and instead of your content you get an error message. The first reaction is usually panic, yet the error message tells you a lot: most of them come down to one or two typical causes, and you can check some of them yourself. This article goes through the eight most common WordPress errors (see also WordPress.org's own list of common errors).

One rule applies to all of them: before you touch anything, check that you have a recent backup. If you do not, ask your hosting provider for one first.

1. "There has been a critical error on this website"

This means a piece of PHP code hit an error that stops the page from loading. The most common cause is a plugin or theme that, after an update, no longer gets along with the others or with the server's PHP version.

WordPress usually sends an email to the admin address in this case, naming the plugin that caused the error and including a link that lets you log in without the broken plugin. I wrote about this in detail in the article on errors after an update.

2. "Error establishing a database connection"

The site cannot reach the database where the content lives. Three typical causes:

• The database credentials have changed, and wp-config.php still has the old ones. This happens after a hosting move or a password change.
• The database server is down or overloaded. This is on the hosting provider's side and may fix itself within minutes.
• The database is corrupted. This is rarer, and it is where you need the backup.

As a first step, check your host's status page or contact support. If everything is fine on their end, the credentials are the suspect.

3. "ERR_TOO_MANY_REDIRECTS" or "redirected you too many times"

The site sends the browser round in circles, for example from http to https and back. This is almost always a configuration clash:

• in WordPress, the site address (Settings → General) is set with http while the server redirects to https;
• the SSL setting of a CDN or proxy (such as Cloudflare) does not match the server's;
• two redirect plugins or rules contradict each other.

It is worth clearing the browser's cookies for the site first, because sometimes an old redirect is just stuck. If it persists, the settings need to be brought in line.

4. "Briefly unavailable for scheduled maintenance. Check back in a minute."

WordPress puts up this message during an update and removes it at the end. If the update was interrupted (the connection timed out, you closed the browser), the message gets stuck.

The fix is simple: in your host's file manager, delete the file called .maintenance in the WordPress root folder. After that, though, check that the interrupted update did not leave a half-installed plugin: look at the Plugins page and update again whatever was left unfinished.

5. "500 Internal Server Error"

This is the least telling one: it only says something broke on the server. Common causes on a WordPress site:

• a corrupted .htaccess file (for example rewritten by a security or caching plugin);
• PHP running out of memory;
• a plugin error that does not make it as far as the "critical error" message.

Here the host's error log tells the truth. On most hosts you will find it in the control panel.

6. "403 Forbidden"

The server refuses access. If everyone sees it, it may be a file permission or .htaccess problem. If only you do, or only from certain places, a firewall or security plugin has probably blocked you: after too many failed logins, for example.

It is not always an error. On my own site, the host's firewall returned 403 to some external testing tools while real visitors reached the site without a problem. A "bad result" like that can be misleading, so it is worth checking from a different network too (such as mobile data).

7. "Your connection is not private"

The browser does not accept the site's SSL certificate. The most common cause is that the certificate has expired and did not renew automatically. Less often, the certificate is issued for a different address (for example only the non-www version).

This is alarming for visitors, and many leave right there. Most hosts provide a free, automatically renewing certificate (Let's Encrypt). If it has expired, you can request it again in your host's control panel.

8. The site does not load at all

No error message, just a blank page or the browser's own "can't be reached" screen. Here the problem sits in front of WordPress:

• The domain has expired. This is the most common case and the easiest to prevent: the renewal notice often goes to an old email address.
• The hosting has been suspended because a payment was missed.
• The DNS settings have changed, and the domain no longer points to the host.

If your domain or hosting is in someone else's name and you cannot reach them, I wrote here about what to do first.

Common WordPress errors: when to call a specialist

• If you do not have a recent backup, do not experiment. One wrong move can turn a fixable error into an unfixable one.
• If it is an online store with orders coming in, every hour of downtime is money.
• If the error keeps coming back, only the symptom was fixed and the cause is still there.

Most of these errors can be prevented with regular updates tested on a copy first, a working backup, and keeping an eye on domain and certificate expiry. That is the core of my maintenance plans. If your site is down right now, write to me and I will take a look.