08Website know-how & errors

Fix error 500 and the white screen of death

Internal Server Error or a blank white page on your Nexthosting website? Find the cause with the error log, .htaccess test, plugins and the PHP version.

In short

A 500 error (“Internal Server Error”) or a blank white page means: your script crashed. The cause is in the error log. Most often it is a faulty plugin or theme, a broken .htaccess, a memory limit that is too small or an unsuitable PHP version. Work through the steps below in order; that is faster than guessing.

What is actually happening?

When the web server (Apache) calls a PHP page and PHP crashes along the way, the visitor gets either the message “500 Internal Server Error” or a blank white page. The latter happens when PHP is not allowed to display errors (for security reasons) and the script aborts before producing output. In WordPress you may also see “critical error” or “There has been a critical error on this website”.

Where things can blow up

Request reaches ApacheRules from .htaccess are read
.htaccess faulty?Yes: immediate 500
PHP runsPlugin, theme, code
Error, memory full or time ran out?Script aborts
500 or white page

Page does not load – what now?

What do you see?

Message "500 Internal Server Error" on all pagesUsually .htaccess or the PHP version

Only one subpageUsually a plugin or a script of that page

White page without textRead the PHP error in the log

Only the admin menu is brokenPlugin or memory limit

The error appeared after an updateRoll back the update or restore a backup

Step 1: Read the error log

The error log is the most important clue. It names the file and line where things blew up.

In the web panel you will find the website’s logs (Web panel access). The exact location can vary by version; look for “Logs” or “Error log” for the website.
Via SFTP, logs are often in a logs folder next to the web directory (Upload files via SFTP).
With WordPress you can have errors written to a file. In wp-config.php, add the following before the line “That’s all, stop editing!”:

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );

The messages then end up in wp-content/debug.log. Remove the lines again after testing and delete the file, because it can contain paths and data.

Typical lines and what they mean:

Entry in the log	Meaning	Solution
`Allowed memory size of … exhausted`	Memory limit reached	Raise the limit, check plugins (step 5)
`Maximum execution time of … exceeded`	Script ran too long	Raise the time limit, split the task into parts
`Uncaught Error: Call to undefined function`	Missing extension or wrong PHP version	Adjust the PHP version, update the plugin
`Parse error: syntax error`	Typo in the code	Undo the last change
`Class not found`	File missing or plugin uploaded incompletely	Upload the plugin again
`.htaccess: Invalid command`	Unknown directive in `.htaccess`	Remove the directive (step 3)
`Premature end of script headers`	PHP terminated	Check the plugin/script
`Permission denied`	File permissions wrong	File permissions
`Can't connect to MySQL` or `Error establishing a database connection`	Is the database reachable? Credentials wrong?	Check `wp-config.php` (database host at Nexthosting usually `localhost`) and look at the database in phpMyAdmin

Step 2: Error after a change?

Ask yourself: what did I change last? An update, a new plugin, a PHP switch, a file in the editor? In nine out of ten cases that is the cause. Undo the last change. If you have a backup, that is often the fastest way: Backups and restoring.

Step 3: Test `.htaccess`

A faulty .htaccess leads to a 500 on the whole site.

Connect via SFTP or open the file manager in the web panel.
Rename .htaccess in the website’s main directory to .htaccess-old. The file is hidden; switch on the display of hidden files.
Open the website. If it works now, the .htaccess was the problem.
With WordPress, you generate a new default file under Einstellungen (Settings), Permalinks, Änderungen speichern (Save Changes). After that, add your own rules back one at a time and test after each.

More about permitted directives in .htaccess basics.

Step 4: Test plugins and theme

With WordPress, plugins cause most errors.

Via SFTP, rename the folder wp-content/plugins to plugins-off. All plugins are now deactivated.
Open the website. If it works, it was a plugin.
Rename the folder back, then rename individual plugin folders one after another until you have found the culprit.
If the error remains, rename the folder of your active theme under wp-content/themes. WordPress then falls back to a default theme.

Help specifically for WordPress: Solving WordPress problems.

Step 5: Memory and time limit

If the log mentions “memory exhausted” or “execution time”, an adjustment in the web panel helps. At Nexthosting you can change PHP settings directly in the control panel without editing files (PHP settings).

Setting	Purpose	Usual value
`memory_limit`	Memory per script	256M (more for large shops)
`max_execution_time`	Runtime of a script	60 to 300 seconds
`upload_max_filesize`	Size of an upload	64M
`post_max_size`	Size of a request	larger than `upload_max_filesize`

The limits of your plan still apply: you cannot set more than the plan allows. If you permanently need more, look at a larger plan.

Step 6: Check the PHP version

Old plugins sometimes do not tolerate new PHP versions, and new ones need a recent one. Web hosting at Nexthosting supports PHP 8.2 to 8.5, with 8.4 as the default. Switch to the previous version as a test and reload the page. If that helps, update the plugin or have it replaced.

Step 7: File permissions and database

Files should usually have 644, folders 755 (File permissions). Permissions such as 777 are wrong and on some servers can themselves cause a 500.
Is the database reachable? Wrong credentials in wp-config.php lead to “Error establishing a database connection”.

When support should help

If you find nothing in the log or the error remains after all steps, open a ticket. Send:

the address of the page,
the exact time of the error,
the lines from the error log,
what you changed last,
what you have already tried.

More under Describing errors well and Support.

Frequently asked questions

Why do I see no error message, just a white page?

For security reasons, PHP is not allowed to show errors in the browser. The messages are in the error log.

Is this a problem with the server?

A 500 is almost always caused by the website itself. If there is a server problem, you will see it on the status page.

Can I fix the error myself if I do not code?

Usually yes: undo the last change, switch off plugins one by one, restore a backup.