101: The Basics of Website Troubleshooting

Common WordPress Errors Explained and Resolved

Learn the cause patterns behind the most frequent failures and the safe steps to fix them quickly.

Overview

WordPress powers over 40% of the web. Even small misconfigurations or plugin conflicts can lead to downtime, broken pages, or locked admin access. This lesson walks through the most frequent WordPress errors—404, 500, 403, database failures, WSOD, and plugin/theme conflicts—and provides step-by-step recovery workflows using built-in tools and safe file/database edits.

Why These Errors Matter

Visual emphasizing downtime impact on SEO. — Recover quickly, then validate to prevent repeat incidents.

Every minute of downtime affects SEO, user trust, and revenue. Most WordPress errors follow predictable patterns. With the right tools and a calm, methodical approach, you can resolve them quickly and prevent recurrence.

1. 404 Not Found

WordPress permalinks screen. — Refresh permalinks, verify content, then check rewrite rules.

Symptoms: Page shows “404 Not Found”

Causes: Broken permalinks, missing content, incorrect rewrite rules

The Fix Path

Re-save permalinks: Settings → Permalinks → Save Changes
Confirm the content exists and is published
Replace .htaccess with WordPress default rules if corrupted

2. 500 Internal Server Error

500 Internal Server Error diagnostic view. — Fixing 500 Errors — Logs, Recovery Mode, .htaccess, Memory

Symptoms: Entire site shows a 500 error

Causes: Fatal PHP error, corrupted .htaccess, memory exhaustion

The Fix Path

Enable debug logging in wp-config.php and review debug.log
Use Recovery Mode to pause the failing plugin or theme
Replace .htaccess with default rules
Increase PHP memory limit if logs show exhaustion

3. 403 Forbidden

403 Forbidden screen with file permission values. — Restore correct permissions and remove blocking rules safely.

Symptoms: Access denied to site or /wp-admin

Causes: Incorrect permissions, firewall blocks, .htaccess deny rules

The Fix Path

Set file permissions: files = 644, folders = 755, wp-config.php = 440 or 400
Temporarily disable security plugins or review firewall logs
Check .htaccess for deny directives

4. Database Connection Errors

Database connection error screen. — Verify credentials, confirm DB service, repair safely if needed.

Symptoms: “Error establishing a database connection”

Causes: Incorrect credentials, database server down, corrupted tables

The Fix Path

Verify DB settings in wp-config.php (NAME, USER, PASSWORD, HOST)
Check database server status via hosting panel
Enable repair mode if indicated

define( ‘WP_ALLOW_REPAIR’, true );

Option 1 (No SSH): WP_ALLOW_REPAIR + /wp-admin/maint/repair.php
Option 2 (With SSH/WP-CLI): wp db repair
Run repair via /wp-admin/maint/repair.php then remove the constant immediately.

WSOD & Conflicts

WSOD and critical error display. — Recover access, identify the cause, replace the failing extension.

5. White Screen of Death (WSOD)

Symptoms: Blank page or “There has been a critical error”
Fix: Use Recovery Mode, check debug.log for stack trace, roll back extension.

6. Plugin & Theme Conflicts

Symptoms: Site breaks after activation or update
Fix: Recovery Mode, rename folder via SFTP if locked out, update or replace.

After-Action Checklist

✓

Clear all caches (page, object, CDN).

✓

Re-test in incognito/private browser window.

✓

Review Site Health and apply Sucuri WordPress Security best practices.

Key Takeaways

→Each error type has a known cause and a safe fix path.
→Recovery Mode and debug logging are essential for non-invasive troubleshooting.
→File permissions, .htaccess, and database credentials are common failure points.
→Post-repair validation ensures stability and prevents recurrence.