The dreaded 500 internal server error. It always seems to come at the most in inopportune time and you’re suddenly left scrambling to figure out how to get your WordPress site back online.Â ð Trust us, we’ve all been there. Other errors that behave similarly that you might have also seen include the frightening error establishing a database connection and the dreaded white screen of death. But from the moment your site goes down you’re losing visitors and customers. Not to mention it simply looks bad for your brand.
Today we’re going to dive into the 500 internal server error and walk you through some ways to get your site back online quickly. Read more below about what causes this error andÂ what you can do to prevent it in the future.
When you visit a website your browser sends a request over to the server where the site is hosted. The server takes this request, processes it, and sends back the requested resources (PHP, HTML, CSS, etc.) along with an HTTP header. The HTTP also includes what they call an HTTP status code. A status code is a way to notify you about the status of the request. It could be a 200 status code which means “Everything is OK” or a 500 status code which means something has gone wrong.
There are a lot of different types of 500 status error codes (500, 501, 502, 503, 504, etc.) and they all mean something different. In this case, a 500 internal server error indicates indicates that the server encountered an unexpected condition that prevented it from fulfilling the requestÂ (RFC 7231, section 6.6.1).
500 Internal Server Error Variations
Due to the various web servers, operating systems, and browsers, a 500 internal server error can present itself in a number of different ways. But they are all communicating the same thing. Below are just a couple of the many different variations you might see on the web:
- “500 Internal Server Error”
- “HTTP 500”
- “Internal Server Error”
- “HTTP 500 – Internal Server Error”
- “500 Error”
- “500 – Internal Server Error”
- “500 Internal Server Error. Sorry something went wrong.”
- “500. That’s an error. There was an error. Please try again later. That’s all we know.”
- “The website cannot display the page – HTTP 500.”
- A blank white screen
You might also see this message accompanying it:
The server encountered an internal error or misconfiguration and was unable to complete your request. Please contact the server administrator, firstname.lastname@example.org and inform them of the time the error occurred, and anything you might have done that may have caused the error. More information about this error may be available in the server error log.
Where should you start troubleshooting when you see a 500 internal server error on your WordPress site? Sometimes you might not even know where to begin. Typically 500 errors are on the server itself, but from our experience, these errors originate from two things, the first isÂ user error (client-side issue), and the second is that there is a problem with the server.Â So weâll dive into a little of both.
Check out these common causes and ways to fix the 500 internal server error and get back up and running in no time.
1. Try Reloading the Page
This might seem a little obvious to some, but one of the easiest and first things you should try when encountering a 500 internal server error is to simply wait a minute or so andÂ reload the pageÂ (F5 or Ctrl + F5). It could be that the host or server is simply overloaded and the site will come right back. While youâre waiting, you could also quickly try a different browser to rule that out as an issue.
Another thing you can do is to paste the website intoÂ downforeveryoneorjustme.com. This website will tell you if the site is down or if itâs a problem on your side. A tool like this checks the HTTP status code that is returned from the server. If it’s anything other than a 200 “Everything is OK” then it will return a down indication.
We’ve also noticed that sometimes this can occur immediately after you update a plugin or theme on your WordPress site. Typically this is on hosts that aren’t setup properly. What happens is they experience a temporary timeout right afterwards. However, things usually resolve themselves in a couple seconds and therefore refreshing is all you need to do.
2. Clear Your Browser Cache
Clearing your browser cache is always another good troubleshooting step before diving into deeper debugging on your site.Â Below are instructions on how to do it in the various browsers:
3. Check Your Server Logs
YouÂ should also take advantage of yourÂ error logs. If you’re a Kinsta client, you can easily see errors in the log viewer in the MyKinsta dashboard. This can help you quickly narrow down the issue, especially if itâs resulting from a plugin on your site.
If your host doesnât have a logging tool, you can also add the following code to your wp-config.php file to enable logging:
define( 'WP_DEBUG', true ); define( 'WP_DEBUG_LOG', true ); define( 'WP_DEBUG_DISPLAY', false );
The logs are typically located in the /wp-content directory. Others, like here at Kinsta might have a dedicated folder called âlogsâ.
You can also check the log files in Apache and NGINX, which are commonly located here:
- Apache:Â /var/log/apache2/error.log
- NGINX:Â /var/log/nginx/error.log
If you’re a Kinsta client you can also take advantage of ourÂ analytics toolÂ to get a breakdown of the total number of 500 errors and see how often and when they are occurring. This can help you troubleshoot if this is an ongoing issue, or perhaps something that has resolved itself.
If the 500 error is displaying because of a fatal PHP error, you can also try enabling PHP error reporting. Simply add the following code to the file throwing the error. Typically you can narrow down the file in the console tab of Google Chrome DevTools.
ini_set('display_errors', 1); ini_set('display_startup_errors', 1); error_reporting(E_ALL);
And you might need to also modify your php.ini file with the following:
display_errors = on
4. Error Establishing a Database Connection
500 internal server errors can also occur from a database connection error. Depending upon your browser you might see different errors. But both will generate a 500Â HTTP status codeÂ regardless in your server logs.
Below is an example of what an “error establishing a database connection” message looks like your browser. The entire page is blank because no data can be retrievedÂ to render the page, as theÂ connection is not working properly. Not only does this break the front-end of your site, but it will also prevent you from accessing yourÂ WordPress dashboard.
So why exactly does this happen? Well, here are a fewÂ common reasons below.
- The most common issue is that yourÂ database login credentialsÂ are incorrect. Your WordPress site uses separate login information to connect to its MySQL database.
- Your database is corrupted. With so many moving parts with themes, plugins, and users constantly deleting and installing them, sometimes databases get corrupted. This can be due to a missing or individually corrupted table, or perhaps some information was deleted by accident.
- You may haveÂ corrupt filesÂ in your WordPress installation. This can even happen sometimes due to hackers.
- Issues with your database server. A number of things could be wrong on the web hosts end, such as the database being overloaded from a traffic spike or unresponsive from too many concurrent connections. This is actually quite common with shared hosts as they are utilizing the same resources for a lot of users on the same servers.
Check out our in-depth post on how to fix the error establishing a database connection in WordPress.
5. Check Your Plugins and Themes
Third-party plugins and themes can easily cause 500 internal server errors. We’ve seen all types cause them here at Kinsta, from slider plugins to ad rotator plugins. A lot of times you should see the error immediately after installing something new or running an update. This is one reason why we always recommend utilizing a staging environment for updates or at least running updates one by one. Otherwise, if you encounter a 500 internal server error you’re suddenly scrambling to figure out which one caused it.
A few ways you can troubleshoot this is by deactivating all your plugins. Remember, you wonât lose any data if you simply deactivate a plugin. If you can still access your admin, a quick way to do this is to browse to âPluginsâ and select âDeactivateâ from the bulk actions menu. This will disable all of your plugins.
If this fixes the issue youâll need to find the culprit. Start activating them one by one, reloading the site after each activation. When you see the 500 internal server error return, youâve found the misbehaving plugin. You can then reach out to the plugin developer for help or post a support ticket in the WordPress repository.
If you canât access your admin you can FTP into your server and rename your plugins folder to something like plugins_old. Then check your site again. If it works, then you will need to test each plugin one by one. Rename your plugin folder back to âpluginsâ and then rename each plugin folder inside of if it, one by one, until you find it. You could also try to replicate this on a staging site first.
Always makes sure your plugins, themes, and WordPress core areÂ up to date. AndÂ check to ensure you are running a supported version of PHP. If it turns out to be a conflict with bad code in a plugin, you might need to bring in aÂ WordPress developerÂ to fix the issue.
6. Reinstall WordPress Core
Sometimes WordPress core files can get corrupted, especially on older sites. It’s actually quite easy to re-upload just the core of WordPress without impacting your plugins or themes. We have an in-depth guide with 5 different ways to reinstall WordPress. And of course, make sure to take a backup before proceeding. Skip to one of the sections below:
7. Permissions Error
A permissions error with a file or folder on your server can also cause a 500 internal server error to occur.Â Here are some typical recommendations for permissions when it comes to file and folder permissions in WordPress:
- All files should be 644 (-rw-r–r–) or 640.
- All directories should be 755 (drwxr-xr-x) or 750.
- No directories should ever be given 777, even upload directories.
- Hardening: wp-config.php could also be set to 440 or 400 to prevent other users on the server from reading it.
See the WordPress Codex article onÂ changing file permissionsÂ for a more in-depth explanation.
You can easily see your file permissions with an FTP client (as seen below). You could also reach out to your WordPress host support team and ask them to quickly GREP file permissions on your folders and files to ensure they’re setup properly.
8. PHP Memory Limit
A 500 internal server error could also be caused byÂ exhausting the PHP memory limit on your server. You could try increasing the limit. Follow the instructions below on how to change this limit in cPanel, Apache, your php.ini file, and
Increase PHP Memory Limit in cPanel
If you’re running on a host that uses cPanel, you can easily change this from the UI. Under Software click on “Select PHP Version.”
Click on “Switch to PHP Options.”
You can then click on the
memory_limit attribute and change its value. Then click on “Save.”
Increase PHP Memory Limit in Apache
.htaccess file is a special hidden file thatÂ contains various settings you can use to modify the server behavior, right down to a directory specific level. FirstÂ login to your site via FTPÂ or SSH, take a look at your root directory and see if there is a
.htaccess file there.
If there is you can edit that file to add the necessary code for increasing the upload limit. Most likely it is set at 64M or below, you can try increasing this value.
php_value memory_limit 128M
Increase PHP Memory Limit in php.ini File
If the above doesn’t work for you might try editing your
php.ini file.Â Login to your site via FTPÂ or SSH, go to your siteâs root directory and open or create a
If the file was already there, search for the three settings and modify them if necessary. If you just created the file, or the settings are nowhere to be found you can paste the code below. You can modify of course the values to meet your needs.
memory_limit = 128M
Some shared hosts might also require that you add theÂ suPHP directive in your
.htaccess file for the above
php.ini file settings to work. To do this, edit your
.htaccess file, also located at the root of your site, and add the following code towards the top of the file:
<IfModule mod_suphp.c> suPHP_ConfigPath /home/yourusername/public_html </IfModule>
If the above didn’t work for you, it could be that your host has the global settings locked down and instead have it configured to utilize
.user.ini files.Â To edit your
.user.ini file,Â login to your site via FTPÂ or SSH, go to your siteâs root directory and open or create a
.user.ini file. You can then paste in the following code:
memory_limit = 128M
Increase PHP Memory Limit in wp-config.php
The last option is not one we are fans of, but if all else fails you can give it a go. First,Â login to your site via FTPÂ or SSH,Â and locate your wp-config.php file, which is typically in the root of your site.
Add the following code to the top of your
You can also ask your host if you’re running into memory limit issues. We utilize New Relic and other troubleshooting methods here at Kinsta to help clients narrow down what plugin, query, or script might be exhausting the limit. You can also use your own customÂ New Relic key.
9. Problem With Your .htaccess File
Kinsta only uses Nginx, but if you’re using a WordPress host that is running Apache, it could very well be that your
.htaccess file has a problem or has become corrupted. Follow the steps below to recreate a new one from scratch.
First,Â login to your site via FTPÂ or SSH,Â and rename your
.htaccess file to
Normally to recreate this file you can simply re-save your permalinks in WordPress. However, if you’re in the middle of a 500 internal server error you most likely can’t access your WordPress admin, so this isn’t an option. Therefore you can create a new
.htaccess file and input the following contents. Then upload it to your server.
# BEGIN WordPress <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteRule ^index.php$ - [L] RewriteCond % !-f RewriteCond % !-d RewriteRule . /index.php [L] </IfModule> # END WordPress
See the WordPress Codex for more examples, such as a default
.htaccess file for multisite.
10. Coding or Syntax Errors in Your CGI/Perl Script
500 errors being caused by errors in CGI and Perl is a lot less common than it used to be. Although it’s still worth mentioning, especially for those using cPanel where there are a lot of one-click CGI scripts still being used. As AEM on Stack Overflow says:
CGI has been replaced by a vast variety of web programming technologies, including PHP, various Apache extensions like mod_perl, Java of various flavors and frameworks including Java EE, Struts, Spring, etc, Python-based frameworks like Django, Ruby on Rails and many other Ruby frameworks, and various Microsoft technologies.
Here are a few tips when working with CGI scripts:
- When editing, always used a plain text editor, such as Atom, Sublime, or Notepad++. This ensures they remain in ASCII format.
- Ensure correct permissions of chmod 755 are used on CGI scripts and directories.
- Upload your CGI scripts in ASCII mode (which you can select in your FTP editor) into the cgi-bin directory on your server.
- Confirm that the Perl modules you require for your script are installed and supported.
11.Â ServerÂ Issue (Check With Your Host)
Finally, because 500 internal server errors can also occur from PHP timing out or fatal PHP errors with third-party plugins, you can always check with your WordPress host.Â Sometimes these errors can be difficult to troubleshoot without an expert. Here are just a few common examples of some errors that trigger 500 HTTP status codes on the server that might have you scratching your head.Â ð¤
PHP message: PHP Fatal error: Uncaught Error: Call to undefined function mysql_error()...
PHP message: PHP Fatal error: Uncaught Error: Cannot use object of type WP_Error as arrayÂ in /www/folder/web/shared/content/plugins/plugin/functions.php:525
We monitor all client’s sites here at Kinsta and are automatically notified when these types of errors occur. This allows us to be pro-active and start fixing the issue right away. We also utilize LXD managed hosts and orchestrated LXC software containers for each site. This means thatÂ every WordPress site is housed in its own isolated container, which has all of the software resources required to run it (Linux, Nginx, PHP, MySQL). The resources are 100% private and are not shared with anyone else or even your own sites.
PHP timeouts could also occur from the lack of PHP workers,Â although typically these cause 504 errors, not 500 errors. TheseÂ determine how many simultaneous requests your site can handle at a given time. To put it simply, each uncached request for your website is handled by a PHP Worker.
When PHP workers are already busy on a site, they start to build up a queue. Once youâve reached your limit of PHP workers, the queue starts to push out older requests which could result in 500 errors or incomplete requests. Read our in-depth article about PHP workers.
Monitor Your Site
If you’re worried about these types of errors happening on your site in the future, you can also utilize a tool likeÂ updown.ioÂ to monitor and notify you immediately if they occur. It periodically sends an HTTP HEAD request to the URL of your choice. You can simply use your homepage. The tool allows you to set check frequencies of:
- 15 seconds
- 30 seconds
- 1 minute
- 2 minutes
- 5 minutes
- 10 minutes
It will send you an email if and when your site goes down. Here is an example below.
This can be especially useful if youâre trying to debug a faulty plugin or are on a shared host, who tend to overcrowd their servers. This can give you proof of how often your site might actually be doing down (even during the middle of the night). Thatâs why we always recommend going with a managed WordPress host. Make sure to check out our post that explores the top 9 reasons to chooseÂ managed WordPress hosting.
500 internal server errors are always frustrating, but hopefully now you know a few additional ways to troubleshoot them to quickly get your site back up and running. Remember, typically these types of errors are caused by third-party plugins, fatal PHP errors, database connection issues, problems with your .htaccess file or PHP memory limits, and sometimes PHP timeouts.
Was there anything we missed? Perhaps you have another tip on troubleshooting 500 internal server errors. If so, let us know below in the comments.