Fix WordPress 500 Internal Server Error

Published April 21, 2026

Fix WordPress 500 Internal Server Error

A 500 Internal Server Error means something went wrong on the server but the server cannot be more specific. In WordPress, the usual suspects are .htaccess corruption, plugin conflicts, PHP memory limits, and PHP version mismatches.

Step 1: Regenerate .htaccess

The most common cause. Rename your .htaccess file to .htaccess_old via FTP or your file manager. If the 500 error disappears, go to WordPress Admin → Settings → Permalinks and click Save Changes to regenerate a clean .htaccess.

Step 2: Increase PHP Memory Limit

Add to wp-config.php above the "That's all" line:

define('WP_MEMORY_LIMIT', '256M');

Step 3: Deactivate All Plugins

Rename /wp-content/plugins/ to plugins_off/ via FTP. If the error clears, reactivate plugins one by one to identify the conflict.

Step 4: Switch to Default Theme

Rename your theme folder to force the default theme. A theme with a PHP fatal error can cause 500 errors.

Step 5: Check PHP Error Logs

Enable WP_DEBUG and WP_DEBUG_LOG in wp-config.php. The /wp-content/debug.log file will show the exact PHP error causing the 500 response.

Step 6: Check File Permissions

Directories should be 755, files 644. Overly restrictive permissions prevent PHP from reading necessary files.

Step 7: Contact Hosting Support

If none of the above resolves the issue, the problem may be at the server level. SiteICO's support team can check server error logs and PHP configuration directly.