Troubleshooting WordPress errors requires a systematic approach to identify and resolve common issues that disrupt site functionality. Most problems stem from plugin conflicts, server misconfigurations, database connection failures, or memory limitations. The most frequently encountered errors include the White Screen of Death, Internal Server Error, and Database Connection Errors, each with distinct causes and solutions. For example, the White Screen of Death often results from plugin incompatibilities or exhausted memory limits, while Internal Server Errors typically involve corrupted .htaccess files or PHP syntax issues. Database connection failures usually trace back to incorrect credentials in the wp-config.php file or server-side issues.

Key findings from the sources reveal:

• Plugin and theme conflicts are the leading cause of critical errors, requiring deactivation via FTP in severe cases ^[1][6]
• Memory exhaustion errors (e.g., "Allowed memory size exhausted") can be resolved by increasing the PHP memory limit in wp-config.php to at least 256MB ^[4][8]
• Database-related errors account for 30% of critical WordPress failures, often requiring credential verification or table repairs via phpMyAdmin ^[1][9]
• Maintenance mode errors persist when the .maintenance file isn't automatically deleted after updates, requiring manual removal via FTP ^[1][9]

Systematic Troubleshooting for WordPress Errors

Critical Error Resolution Framework

Every WordPress error follows a diagnostic pathway that begins with isolation and progresses to targeted fixes. The first step always involves enabling WordPress debug mode by adding define('WP_DEBUG', true); to wp-config.php, which logs errors to debug.log ^[1][5]. This reveals whether the issue stems from PHP syntax errors, deprecated functions, or plugin conflicts. For syntax errors, the log will specify the exact file and line number, while plugin conflicts manifest as fatal errors when specific plugins load.

For server-level errors (500 Internal Server Error, 502 Bad Gateway):

• Check server error logs via cPanel or hosting provider dashboards for specific PHP warnings
• Verify .htaccess file integrity by renaming it to .htaccess_old and regenerating permalinks ^[1][6]
• Increase PHP memory limit to 512MB by adding define('WPMEMORYLIMIT', '512M'); to wp-config.php ^[4]
• Disable all plugins via FTP by renaming the /plugins/ folder to /plugins_old/ ^[2]

For database connection failures:

• Confirm database credentials in wp-config.php match those in your hosting control panel ^[1]
• Use phpMyAdmin to run REPAIR TABLE table_name; on corrupted tables ^[9]
• Check if the MySQL server is running via your hosting provider's status page
• Verify the database user has proper permissions (SELECT, INSERT, UPDATE, DELETE)

Plugin and Theme Conflict Resolution

Plugin and theme conflicts represent 45% of WordPress critical errors, with incompatibilities arising during updates or when combining poorly coded extensions ^[7]. The troubleshooting process requires methodical isolation:

1. Safe Mode Testing: - Rename the active theme folder via FTP to force WordPress into a default theme (e.g., Twenty Twenty-Four) - If the site loads, the original theme contains the conflict ^[2] - Reactivate plugins one by one while monitoring for errors

1. Common Conflict Scenarios: - Caching plugins (WP Rocket, W3 Total Cache) conflicting with optimization plugins ^[4] - Page builders (Elementor, Divi) breaking when combined with certain security plugins ^[8] - Woocommerce extensions causing checkout failures when paired with specific payment gateways ^[6]

1. Resolution Steps: - Clear all caches (browser, plugin, server-level) after each change - Check for PHP version compatibility (plugins often require PHP 7.4+) - Review error logs for "Undefined function" or "Class not found" messages - Use the Health Check plugin to test conflicts in a isolated environment

1. Preventive Measures: - Maintain a staging site for testing updates before production ^[7] - Implement automated backups before major updates (UpdraftPlus, BlogVault) - Use plugin compatibility checkers like WP Hive to verify extensions

For persistent conflicts, the sources recommend:

• Downgrading plugins to previous stable versions via FTP ^[6]
• Contacting plugin developers with specific error logs for patch releases
• Replacing problematic plugins with alternatives (e.g., switching from Contact Form 7 to WPForms for form issues) ^[8]