A 500 internal server error in WordPress almost always comes from a corrupted .htaccess file, a plugin conflict, or exceeded PHP resource limits — fixing it usually takes under ten minutes once you know which of the three is responsible.
What Triggers a 500 Internal Server Error
Unlike the critical error message, the 500 error is a raw server-level response, so WordPress doesn’t show you a friendly explanation. It typically happens after:
- Installing or updating a plugin or theme
- Editing the .htaccessfile manually
- Hitting your host’s PHP memory or execution time limit
- File permissionissues on core WordPress files
- A corrupted wp-config.php
How to Fix 500 Internal Server Error in WordPress
Step 1: Regenerate the .htaccess File
Log into your hosting File Manager or FTP, navigate to the root folder, and rename ‘.htaccess’ to ‘.htaccess_old’. Then go to Settings > Permalinks in wp-admin and click Save Changes — WordPress automatically generates a fresh, clean .htaccess file.
Step 2: Increase the PHP Memory Limit
Add this to your ‘wp-config.php’ file:
- ‘define( ‘WP_MEMORY_LIMIT’, ‘256M’ );’
If you have server access, also raise it in ‘php.ini’:
- ‘memory_limit = 256M’
Step 3: Deactivate Plugins One by One
Rename the ‘/wp-content/plugins’ folder via FTP to deactivate everything. If the error goes away, rename plugin folders back individually to isolate the faulty one.
Step 4: Re-upload WordPress Core Files
Download a fresh copy of WordPress core from wordpress.org, then re-upload the ‘wp-admin’ and ‘wp-includes’ folders (never overwrite ‘wp-content’ — that holds your themes, plugins, and uploads).
Step 5: Check File & Folder Permissions
Correct permissions should be 755 for folders and 644 for files. Incorrect permissions (like 777) can trigger a 500 error on some hosts for security reasons.
Step 6: Review Your Server Error Logs
Ask your host for the raw Apache/Nginx error log, or check it yourself via cPanel’s “Errors” tool — it often names the exact file and line causing the failure.
Common 500 Error Triggers and Fixes
| Trigger | Symptom | Recommended Fix |
| Corrupted .htaccess | Error appears site-wide, including wp-admin | Regenerate via Permalinks settings |
| Plugin conflict | Error started right after a plugin update | Deactivate plugins via FTP one by one |
| PHP memory limit | Error on specific pages only (e.g., checkout) | Raise WP_MEMORY_LIMIT to 256M |
| Wrong file permissions | Error on uploads or media pages | Set folders to 755, files to 644 |
| Corrupted core files | Error persists after all other fixes | Re-upload wp-admin & wp-includes |
When to Escalate to Your Host
- If the error log shows a server-level timeout (not PHP), it’s a hosting resource limit issue
- Shared hosting plans often cap execution time — ask your host to raise it temporarily while you debug
- Managed WordPress hosts usually resolve 500 errors from their end within minutes if you share your debug.log
