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 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.

Common WordPress Errors and Fixes

1. 404 Not Found
   • Symptoms: Page shows “404 Not Found”
   • Causes: Broken permalinks, missing content, incorrect rewrite rules
   • Fix:
     • 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
   • Symptoms: Entire site shows a 500 error
   • Causes: Fatal PHP error, corrupted .htaccess, memory exhaustion
   • Fix:
     • 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
   • Symptoms: Access denied to site or /wp-admin
   • Causes: Incorrect file/folder permissions, firewall blocks, .htaccess deny rules
   • Fix:
     • 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
   • Symptoms: “Error establishing a database connection”
   • Causes: Incorrect credentials, database server down, corrupted tables
   • Fix:
     • Verify DB settings in wp-config.php: DB_NAME, DB_USER, DB_PASSWORD, DB_HOST
     • Check database server status via hosting panel
     • Enable repair mode:

define( 'WP_ALLOW_REPAIR', true );

• Visit /wp-admin/maint/repair.php, run repair, then remove the constant
• Or use WP-CLI:
  
  

wp db repair

1. White Screen of Death (WSOD)
   • Symptoms: Blank page or “There has been a critical error on this website”
   • Causes: Fatal PHP error, memory exhaustion
   • Fix:
     • Use Recovery Mode (admin email link) to pause the faulty extension
     • Check debug.log for stack trace
     • Roll back or replace the offending plugin/theme
2. Plugin & Theme Conflicts
   • Symptoms: Site breaks after activation or update
   • Causes: Incompatible versions, deprecated functions, block editor conflicts
   • Fix:
     • Use Recovery Mode to pause the extension
     • If locked out, rename the plugin/theme folder via SFTP
     • Update to a compatible version or replace with a stable alternative

After-Action Checklist

• Clear all caches (page, object, CDN)
• Re-test in incognito/private browser window
• Review Site Health for warnings and recommendations
• Apply hardening best practices from the Sucuri WordPress Security Guide

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