Common WordPress Errors and How to Fix Them

Every WordPress site throws an error sooner or later. One moment the site is fine, the next you’re staring at a blank white page, a scary red error message, or a login screen that won’t stop refreshing. It’s alarming, but it’s also completely normal, and the overwhelming majority of WordPress errors have a known cause and a quick fix.

This guide covers the most common WordPress errors, grouped by what actually causes them, with the exact steps to fix each one. Skip to the error you’re seeing, or read through to understand the patterns behind nearly all of them.

Quick Diagnosis: Match Your Symptom to the Cause

Before digging into individual fixes, most WordPress errors trace back to one of five root causes. This table helps you narrow it down fast.

Before You Touch Anything: Two Rules

Two habits will save you from turning a small problem into a bigger one.

Back up first. Even if you’re confident about the fix, take a backup before making changes. If something goes wrong, you want a way back. If you don’t already have a reliable backup running, Webueno’s Daily Backups handle this automatically so you’re never troubleshooting without a safety net.

Change one thing at a time. The instinct when a site breaks is to update everything, deactivate everything, and change settings all at once. Resist it. If you change five things simultaneously and the site starts working, you won’t know which one fixed it, or which one might cause a new problem later. Isolate variables.

Category 1: Plugin and Theme Conflicts

This is the single most common source of WordPress errors. A plugin update changes something, a theme expects a function that no longer exists, or two plugins fight over the same resource.

The White Screen of Death

Symptom: A completely blank white page, front end, admin, or both. No error message, nothing.

Cause: Almost always a plugin or theme conflict, or the site running out of PHP memory.

Fix:

• Connect via FTP/SFTP and rename your plugins folder to something like plugins-disabled. This deactivates every plugin at once. If the site comes back, rename the folder back and reactivate plugins one at a time, checking the site after each one, until you find the culprit.
• If disabling plugins doesn’t help, switch to a default WordPress theme (like Twenty Twenty-Four) via FTP by renaming your active theme’s folder.
• If neither works, raise your PHP memory limit by adding this line to wp-config.php: define(‘WP_MEMORY_LIMIT’, ‘256M’);

“There has been a critical error on this website”

Symptom: WordPress shows this specific message instead of a blank screen (a more recent, slightly friendlier version of the White Screen).

Cause: Same as above: a fatal PHP error from a plugin, theme, or core conflict.

Fix: WordPress often emails the site admin a recovery link when this happens, allowing you to disable the problematic plugin/theme from a special recovery mode without FTP. If you don’t have that email, follow the same plugin/theme deactivation process as the White Screen of Death.

Login Loop (Redirecting Back to Login)

Symptom: You enter your credentials, the page reloads, and you’re back at the login screen. Repeatedly.

Cause: Corrupted browser cookies, a security plugin misfiring, or an incorrect Site URL/Home URL setting.

Fix:

• Clear your browser cookies and cache, then try again.
• Deactivate plugins via FTP (especially security plugins) as described above.
• Check that WP_HOME and WP_SITEURL in wp-config.php, or the Site Address settings in the database, match your actual domain.

Category 2: Server and File Errors

These errors come from the server environment itself, corrupted files, resource limits, or misconfiguration.

500 Internal Server Error

Symptom: A generic, unhelpful “500 Internal Server Error” with no further detail.

Cause: A corrupted .htaccess file, a plugin/theme conflict, or a PHP memory or execution issue. This is one of the most common and most vague WordPress errors because the server gives you almost no information about what actually broke.

Fix:

• Rename your .htaccess file via FTP (to .htaccess_old), then go to Settings > Permalinks in wp-admin and click Save. This regenerates a fresh htaccess file.
• If that doesn’t help, deactivate plugins one by one via FTP as described earlier.
• Raise your PHP memory limit as shown above.
• Check your hosting error logs for a more specific clue; most hosts expose a raw PHP error log that names the exact file and line causing the crash.

Error Establishing a Database Connection

Symptom: A message saying WordPress cannot connect to its database, often on both the front end and login screen.

Cause: Incorrect database credentials in wp-config.php, a corrupted database, or the database server being down.

Fix:

• Open wp-config.php and confirm the DB_NAME, DB_USER, DB_PASSWORD, and DB_HOST values exactly match what your hosting account shows.
• If credentials are correct, your database tables may be corrupted. Many hosts include a repair tool, or you can add define(‘WP_ALLOW_REPAIR’, true); to wp-config.php and visit yoursite.com/wp-admin/maint/repair.php to run WordPress’s built-in repair.
• If neither resolves it, contact your host; the database server itself may be down.

403 Forbidden Error

Symptom: “403 Forbidden” when trying to access the site or a specific page.

Cause: Incorrect file/folder permissions, a misconfigured security plugin or firewall, or a corrupted .htaccess file.

Fix:

• Reset file permissions to the WordPress standard: folders to 755, files to 644.
• Temporarily disable any security plugin to see if it’s blocking access.
• Regenerate .htaccess the same way described for the 500 error.

404 Not Found on Posts or Pages

Symptom: The homepage works, but individual posts or pages return “404 Not Found.”

Cause: WordPress’s permalink rewrite rules are out of sync, often after a migration, a plugin change, or a custom post type being added.

Fix: Go to Settings > Permalinks in wp-admin and click Save Changes, even without altering anything. This flushes and regenerates the rewrite rules and resolves the vast majority of cases.

Maximum Upload File Size / Memory Exhausted Errors

Symptom: Images or files won’t upload, or you see a “memory exhausted” fatal error.

Cause: Server-side PHP limits (upload_max_filesize, post_max_size, memory_limit) set too low for what you’re trying to do.

Fix: Add these lines to wp-config.php, or ask your host to raise the limits at the server level if wp-config.php changes don’t take effect:

define(‘WP_MEMORY_LIMIT’, ‘256M’);

For upload size limits specifically, this usually needs to be changed in your hosting control panel or a custom php.ini file, since it’s a server-level setting WordPress can’t override alone.

Category 3: Security and Malicious Redirects

Site Redirecting to a Different URL or Spam Page

Symptom: Visiting your site sends you (or your visitors) somewhere else entirely, often spam or malicious content.

Cause: This is a red flag for malware, though it can occasionally be a misconfigured redirect plugin.

Fix:

• Check wp-config.php and your database’s wp_options table for unfamiliar siteurl or home values.
• Deactivate any redirect plugins to rule out misconfiguration.
• If neither explains it, treat this as a likely infection. Scan the site immediately; our guide on WordPress malware removal walks through the full cleanup process, or use a Malware Scanner to confirm.

“This Site May Be Hacked” Warning in Google

Symptom: Google flags your site with a warning in search results or Search Console.

Cause: Confirmed malware or injected spam content that Google’s crawler detected.

Fix: This requires full malware removal followed by a review request in Google Search Console. See our complete guide on cleaning a hacked WordPress site for the step-by-step process.

Category 4: Email and Notification Failures

WordPress Not Sending Emails

Symptom: Contact form submissions, password resets, or notification emails never arrive.

Cause: WordPress’s default mail function (PHP mail()) is unreliable and frequently blocked or flagged as spam by receiving servers. Most hosts don’t fully support it.

Fix: Install an SMTP plugin (like WP Mail SMTP) and connect it to a real email service (Gmail, SendGrid, or your hosting provider’s SMTP). This routes your emails through a proper, authenticated mail server instead of WordPress’s unreliable default method, and resolves the overwhelming majority of email delivery issues.

Category 5: Update and Compatibility Errors

Site Broke After a WordPress, Plugin, or Theme Update

Symptom: Everything was fine, you updated something, and now it isn’t.

Cause: The update introduced a conflict with your specific combination of theme, plugins, and PHP version, one of the most common ways WordPress sites break.

Fix:

• If you can access wp-admin, deactivate the most recently updated plugin and check if the issue resolves.
• If you can’t access wp-admin, roll back the plugin via FTP by replacing it with a backed-up previous version, or deactivate it by renaming its folder.
• This is exactly why testing updates on a staging site before applying them live matters. It is the single biggest differentiator between maintenance plans that prevent this issue and ones that don’t.

“Briefly Unavailable for Scheduled Maintenance” Stuck On

Symptom: The site is stuck showing this maintenance message long after an update should have finished.

Cause: An update process was interrupted (often by a timeout) and left a leftover .maintenance file in place.

Fix: Connect via FTP, navigate to your site’s root directory, and delete the file named .maintenance. The site returns to normal immediately.

Why These Errors Follow Predictable Patterns

Once you’ve seen a handful of WordPress errors, a pattern emerges: almost everything traces back to one of four sources.

• Plugins and themes conflicting with each other or with WordPress core
• Server resources (memory, file limits) being insufficient
• Corrupted files, especially .htaccess and wp-config.php
• Database issues, from wrong credentials to corrupted tables

That’s genuinely useful to know, because it means troubleshooting isn’t about memorizing hundreds of specific errors. It’s about learning this short list of usual suspects and checking them in order: plugins first, then theme, then server limits, then files, then database.

How to Prevent Most of These From Happening

Fixing errors is a skill worth having, but the better skill is not needing it as often. A few habits prevent the majority of what’s in this guide:

• Test updates on staging before applying them live. This alone prevents the most common cause of sudden breakage.
• Keep a recent, verified backup at all times. When something does break, restoring is faster than debugging.
• Update plugins and themes regularly, not all at once after months of neglect. Frequent small updates are far less likely to cause conflicts than one giant batch.
• Remove plugins you don’t use. Every inactive plugin is still a potential conflict waiting to happen.
• Monitor uptime so you find out about an outage in minutes, not from a customer complaint.

When to Stop Troubleshooting and Get Help

Most of the errors above are fixable in a few minutes once you know where to look. But a few situations are worth handing off rather than debugging solo: the fix requires editing the database directly, and you’re not comfortable with that; the site is business-critical and every minute of downtime costs money, you’ve tried the standard fixes and the error persists; or you suspect malware rather than a simple conflict.

At Webueno, WordPress Troubleshooting covers exactly this: fast, structured diagnosis for broken pages, plugin conflicts, PHP errors, database issues, and anything else that takes a site down, handled by a team that documents what they find and fixes the root cause, not just the symptom. And because errors are so often triggered by unsafe updates, our Maintenance service tests updates in staging first specifically to prevent most of what’s covered in this guide from happening in the first place.

Errors Happen. Downtime Doesn’t Have To.

WordPress errors are unavoidable over the life of a site, but they’re rarely mysterious once you know the short list of usual causes: plugins, themes, server limits, files, and the database. Work through them in that order, change one thing at a time, and keep a backup before you start, and you’ll resolve the overwhelming majority yourself.

For the ones that don’t resolve quickly, or for a site where every minute of downtime matters, Webueno’s Troubleshooting service is built to diagnose and fix it fast.

Get your WordPress errors fixed by experts

Frequently Asked Questions

What is the most common WordPress error?

The White Screen of Death and the 500 Internal Server Error are the two most frequently reported WordPress errors. Both are usually caused by a plugin or theme conflict, or a PHP memory limit issue, and both are typically resolved by deactivating plugins one at a time to isolate the cause.

How do I fix a WordPress error without losing my site?

Always back up before making changes. Most fixes (deactivating plugins, switching themes, editing wp-config.php) are reversible, but a backup means you can undo anything that goes wrong. Change one thing at a time so you know exactly what fixed or broke the site.

Why does my WordPress site keep breaking after updates?

Updates occasionally introduce conflicts with your specific combination of plugins, theme, and PHP version. This is one of the most common causes of sudden WordPress errors. Testing updates on a staging site before applying them to your live site prevents the vast majority of these issues.

Can I fix WordPress errors without technical knowledge?

Many common errors (like flushing permalinks for a 404 error, or clearing cookies for a login loop) require no technical skill. Others (editing wp-config.php, using FTP to disable plugins) require basic comfort with files and settings but no coding knowledge. More complex issues, like database corruption or malware, are better handled by a professional.

What should I check first when my WordPress site breaks?

Start with plugins. Deactivate them all (via FTP if you can’t access wp-admin) and see if the issue resolves. If it does, reactivate one at a time to find the culprit. Plugin and theme conflicts cause the majority of WordPress errors, so this single step resolves more issues than any other troubleshooting action.

Is it safe to edit wp-config.php myself?

Yes, as long as you back up the file first (or your whole site) and edit it carefully. It’s a plain text file, and adding a line like the PHP memory limit definition is low-risk. Just avoid deleting existing lines you don’t understand, and always keep a copy of the original before editing.

How do I know if a WordPress error is caused by malware?

Signs include unexpected redirects to unfamiliar sites, a “This site may be hacked” warning in Google, unfamiliar admin users, or spam content appearing on your site. Standard errors like the White Screen or a 404 are usually not malware-related, but redirects and warnings from Google almost always are.

Should I hire someone to fix WordPress errors, or do it myself?

Simple, well-documented errors (permalinks, login loops, memory limits) are reasonable to fix yourself with a guide like this one. For business-critical sites, errors that persist after standard fixes, or anything involving the database or suspected malware, professional troubleshooting is worth it, since a mistake can turn a small problem into a bigger one.