RegisterLogin
WordPress Troubleshooting

How to Fix the 500 Internal Server Error in WordPress

A deep dive into troubleshooting the 500 Internal Server Error in WordPress. Learn how to fix broken .htaccess files, diagnose plugin conflicts, and increase PHP memory.

Nextgen Engineering•
How to Fix the 500 Internal Server Error in WordPress

The 500 Internal Server Error is arguably the most frustrating HTTP status code in web development. Unlike a 404 (Not Found) or a 403 (Forbidden), a 500 error is essentially the server throwing its hands up in the air. The message translates to: “Something has gone horribly wrong deep inside the server infrastructure, but I am not configured to tell you exactly what it is.”

While a 503 Service Unavailable Error usually points to a temporary resource overload (lack of PHP workers), a 500 error almost always points to a hard configuration fault—a syntax error in a critical file, broken routing rules, or a severe plugin conflict that causes PHP to crash instantly.

Because this error usually takes down both your front-end website and your wp-admin dashboard, you have to diagnose it directly from your server’s file system. Here is the step-by-step diagnostic workflow.

1. The Most Likely Culprit: A Corrupt .htaccess File

If you are hosted on an Apache or LiteSpeed server, the .htaccess file controls your URL routing and server directives. If a caching or security plugin writes a malformed line of code into this file (like missing a closing tag or using a deprecated Apache command), the server will instantly crash and throw a 500 error.

  1. Connect to your server via cPanel File Manager or an FTP client like FileZilla.
  2. Navigate to your root directory (public_html).
  3. Ensure you have “Show Hidden Files” enabled, and locate .htaccess.
  4. Right-click and rename it to .htaccess_old. (This completely disables the file).
  5. Open an incognito window and refresh your website.

If the site loads correctly, you have found the issue! Log into your WordPress dashboard, navigate to Settings > Permalinks, and simply click Save Changes at the bottom. This will force WordPress to generate a brand new, clean .htaccess file automatically.

2. Isolate Rogue Plugins via FTP

If the .htaccess file is perfectly fine, the next most common cause is a newly installed or updated plugin that contains a fatal PHP syntax error.

  1. In your File Manager, navigate to wp-content.
  2. Locate the plugins folder.
  3. Rename the folder to plugins_disabled. This forcefully deactivates every single plugin on your site without needing dashboard access.
  4. Refresh your website.

If the 500 error disappears, you know a plugin is at fault. Rename the folder back to plugins. Then, go inside the folder and rename each individual plugin folder one by one (e.g., elementor_disabled, woocommerce_disabled) until the site crashes again. You have now identified the rogue plugin. Delete it and install an older, stable version.

3. Increase the PHP Memory Limit

Sometimes, a massive theme or a heavy backup script will try to load too much data into the server’s RAM at once. If the script hits a hard limit, it doesn’t fail gracefully—it crashes the PHP process, resulting in a 500 error (this is essentially a masked Memory Exhausted Error).

  1. Open your wp-config.php file in the root directory.
  2. Paste the following line of code just before the line that says /* That's all, stop editing! */:
define( 'WP_MEMORY_LIMIT', '512M' );
  1. Save the file. If memory exhaustion was the root cause, your site will come back online immediately.

4. Unmask the Error with WP_DEBUG

If you have tried all the above and are still staring at a white screen, it is time to stop guessing and force the server to tell you exactly what line of code is failing.

  1. Open wp-config.php again.
  2. Find the line that says define( 'WP_DEBUG', false );.
  3. Replace it with these three lines:
define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );
  1. Refresh your broken website to trigger the error again.
  2. Go into your wp-content folder and open the newly created debug.log file.

Scroll to the bottom of the log. You will see a “Fatal Error” entry pointing to the exact file path and line number that crashed the server (e.g., /wp-content/themes/your-theme/functions.php on line 42). You can then edit that file and delete or fix the broken code.

The Advantage of Developer-Friendly Hosting

Diagnosing 500 errors on cheap, restrictive shared hosting is a nightmare. Some entry-level hosts actively block you from editing .htaccess files or accessing raw PHP error logs, leaving you completely helpless when your site goes down.

Nextgen’s WordPress Hosting in Pakistan is built by developers, for developers. Our cPanel environments give you instant, unrestricted access to your PHP error logs, a multi-version PHP selector, and full .htaccess control. More importantly, if a bad plugin update ever triggers a 500 error, our daily automated JetBackup system allows you to roll back your entire website to a perfectly working state with a single click—getting your business back online in seconds.

To prevent recurring server-level memory exhaustion, consider hosting your website on fast NVMe shared hosting with optimized PHP workers.