How to Troubleshoot Plugin, Cache, and Custom Code Conflicts in WordPress

WordPress sites can occasionally encounter issues due to conflicts arising from plugins, caching mechanisms, or custom code. These conflicts may manifest as broken layouts, functionality errors, or unexpected behavior. This guide provides a systematic approach to identify and resolve such conflicts, ensuring your website operates smoothly.​

The troubleshooting process involves isolating the source of the conflict by systematically disabling caching, deactivating plugins, and reviewing custom code. By following these steps, you can pinpoint the exact cause of the issue and implement the necessary fixes.​

1. Bypass Cache and Optimizations

Caching and optimization plugins, such as NitroPack or WP-Rocket, can sometimes interfere with site functionality, especially for non-logged-in users. Temporarily disabling these plugins helps determine if they are the source of the problem.​

Steps:

• Navigate to Plugins > Installed Plugins in your WordPress dashboard.

• Deactivate any caching or optimization plugins.

• Clear your browser cache or use an incognito window to view the site without cached content.​

2. Enable Debugging Mode via SFTP

Activating WordPress debugging mode allows you to log errors and warnings, providing insights into potential issues.​

Steps:

• Connect to your site via an SFTP client (e.g., FileZilla).

• Locate and download the wp-config.php file from your WordPress root directory.

• Open the file in a text editor and add the following lines:​

  define('WP_DEBUG', true); define('WP_DEBUG_LOG', true); define('WP_DEBUG_DISPLAY', false); 

• Save and re-upload the file to your server.​

Errors will now be logged in the wp-content/debug.log file.​

3. Deactivate All Plugins

Disabling all plugins helps determine if a plugin is causing the issue.​

Steps:

• Go to Plugins > Installed Plugins.

• Select all plugins and choose Deactivate from the Bulk Actions dropdown.

• Refresh your site to see if the issue persists.​

4. Remove Custom Code in Theme

Custom code in your theme's files can lead to conflicts, especially after updates.​

Steps:

• Access your theme files via SFTP or the WordPress theme editor.

• Temporarily comment out or remove custom code from files like functions.php.

• Save changes and refresh your site to check for improvements.​

5. Check the Issue

With caching disabled, plugins deactivated, and custom code removed, assess whether the problem still exists.​

• If resolved, the issue likely stemmed from one of these areas.

• If not, consider switching to a default theme to rule out theme-related conflicts.​

6. Reactivate Plugins One by One

To identify the specific plugin causing the conflict, reactivate each plugin individually.​

Steps:

• Activate one plugin at a time.

• After each activation, refresh your site to check for issues.

• Once the problem reappears, you've found the conflicting plugin.​

7. Investigate Further

Upon identifying the problematic plugin or code:​

• Check for available updates.

• Review compatibility with your WordPress version.

• Consult the plugin's support forum or developer for assistance.

• Consider alternative plugins if necessary.

8. Restore Debug Mode

After troubleshooting, disable debugging to prevent unnecessary logging.

Steps:

• Edit the wp-config.php file.

• Change the debug lines to:​

  define('WP_DEBUG', false); define('WP_DEBUG_LOG', false); define('WP_DEBUG_DISPLAY', false); 

• Save and re-upload the file to your server.

• Switch to a Default Theme: If issues persist, activate a default WordPress theme (e.g., Twenty Twenty-One) to determine if your theme is the culprit.

• Use Browser Console Logs: Open your browser's developer console (F12) to check for JavaScript errors that might indicate conflicts.

• Test on a Staging Site: Before making changes to your live site, replicate the issue on a staging environment for safe testing.​