Error 500 · server

500 Internal Server Error

Ben Johnson · last verified 2026-08-02

Also seen as: HTTP 500 · Internal Server Error · white screen of death

What it actually means

500 is the server’s way of saying “your code or configuration failed and I am not going to tell the public why.” That secrecy is a security feature, not an obstacle: error messages leak file paths, database names, and credentials.

The error page is not the diagnostic. The error log is. Everything below is about getting to the log, and then reading it.

A blank white page instead of an error page is the same problem seen through PHP’s display settings rather than the web server’s.

Why it happens

A PHP fatal error

A syntax error, a call to an undefined function, an incompatible PHP version, or a hard memory-limit hit. This is by far the most common cause, and it usually appeared the moment you edited a file, updated a plugin, or changed PHP version.

A bad .htaccess directive

A typo, or a directive the server does not permit. Shared hosts disable directives that could affect other accounts, and using one produces an immediate 500 on every request to that directory and everything below it.

Wrong file permissions

PHP files that are group- or world-writable are refused outright by suEXEC as a security measure. This bites after uploading files from Windows or extracting an archive that carried its own permission bits.

Memory exhaustion

A script that tries to allocate more memory than the account is allowed is killed mid-execution. Image processing and large imports are the usual triggers. The log line names an allowed memory size explicitly.

How to fix it

1. Read the error log first

Everything else is guessing until you have done this. The log is in your control panel under Error Log, or as error_log in the directory where the failure happened.

Read the most recent entry and match its timestamp to when you loaded the page. The log names the file and line number. In practice this identifies the cause outright in most cases.

2. Rule out .htaccess in ten seconds

Rename it and reload:

mv .htaccess .htaccess.bak

If the 500 disappears, the file is the cause. Restore it and bisect — comment out half the directives, reload, repeat. If your site is WordPress and you deleted rather than renamed the file, regenerate the default rules by visiting Settings → Permalinks and clicking Save.

3. Turn on errors for yourself only

Never enable public error display on a live site. In WordPress, log to a file instead:

define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false); // keep them off the page

Errors then land in wp-content/debug.log. Turn all three off again when you are finished — a readable debug.log is an information leak.

4. Correct the permissions

Directories 755, files 644, and never 777 on anything:

find . -type d -exec chmod 755 {} \;
find . -type f -exec chmod 644 {} \;

If a tutorial tells you to chmod 777 a directory to fix an upload problem, it is wrong and it will produce a 500 under suEXEC, on top of being unsafe.

5. Disable plugins without the admin panel

If the 500 locks you out of /wp-admin, disable everything over FTP by renaming the directory:

mv wp-content/plugins wp-content/plugins.off

If the site returns, rename it back and re-enable plugins one at a time until it breaks again. The last one you enabled is the culprit.

On CWP specifically

Related errors

• 508 508 Resource Limit Is Reached
  Your account hit its CPU, memory, or concurrent-process ceiling, so the server refused the request instead of letting your site destabilise the machine.
• 403 403 Forbidden
  The server found what you asked for and refused to serve it — a permissions, index, or access-rule problem rather than a missing file.
• DB Error establishing a database connection
  PHP reached the point of trying to talk to MySQL and failed — because the credentials are wrong, the hostname is wrong, or the database server refused the connection.
• REDIR ERR_TOO_MANY_REDIRECTS
  Two rules are sending the browser back and forth at each other, so it gives up after about twenty hops rather than looping forever.
• 404 404 Not Found
  The server is working and answered you — it just has nothing at the address you asked for.
• 502 502 Bad Gateway
  A server in front passed your request to a server behind it, and got back a broken response or none at all.
• 530 FTP 530 Login authentication failed
  The FTP server rejected your credentials — usually the wrong username format, or a client trying to connect without TLS.
• MEM Allowed memory size exhausted
  A PHP script asked for more memory than your account allows, so it was killed part-way through.
• WSOD White screen of death
  PHP hit a fatal error and error display is turned off, so the server sent an empty page instead of a message.
• 413 413 Payload Too Large
  You tried to upload something bigger than the server accepts, and it rejected the request before reading it all.