When DirectAdmin WordPress Manager throws a 500 Internal Server Error and displays an empty page, it indicates that there is likely a problem with the WordPress Manager plugin or its configuration. Here are steps you can take to troubleshoot and resolve the issue:

1. Check Error Logs:

   • Look into the server's error logs for more specific information about what is causing the 500 error. These logs are typically located in /var/log/httpd/ or a similar directory.

2. Verify PHP Version and Configuration:

   • Ensure that the PHP version being used by DirectAdmin matches the requirements of the WordPress Manager plugin.

3. Check Plugin Compatibility:

   • Confirm that the WordPress Manager plugin is compatible with your version of DirectAdmin and the installed version of WordPress.

4. Reinstall WordPress Manager:

   • Remove the WordPress Manager plugin from DirectAdmin and then reinstall it. This can sometimes resolve issues with corrupt or misconfigured plugin files.

5. Check for Plugin Conflicts:

   • Disable any other DirectAdmin plugins or WordPress plugins that might be conflicting with the WordPress Manager. Then, try accessing it again.

6. Verify Directory Permissions:

   • Ensure that the directories and files related to WordPress Manager have correct permissions. Directories should typically be set to 755 and files to 644.

7. Check for Disk Space and Quotas:

   • Make sure there is enough disk space available on the server and that user quotas are not being exceeded.

8. Update DirectAdmin and WordPress:

   • Ensure that both DirectAdmin and WordPress are running the latest versions. Outdated software can sometimes cause compatibility issues.

9. Check .htaccess File:

   • Look for any issues in the .htaccess file in the WordPress installation directory. Incorrect configurations in this file can lead to server errors.

10. Increase PHP Memory Limit:

    • In the php.ini file, increase the memory_limit setting to ensure that WordPress has enough memory to function properly.

11. Contact DirectAdmin Support:

    • If none of the above steps resolve the issue, consider reaching out to DirectAdmin support or the community forums for further assistance.

12. Contact WordPress Manager Developer:

    • If WordPress Manager is a third-party plugin, reach out to the plugin developer or their support channels for specific guidance.

Always ensure that you have backups of your website and data before making significant changes to your server or web applications. This way, you can easily restore functionality if any issues arise during troubleshooting.