One of the more common errors which may appear on your WordPress website is a 500 Internal Server Error. If you encounter one, follow the steps below to get your website back online.
Corrupt .htaccess File
A corrupt .htaccess file is a common culprit. To determine fault, connect to your FTP server and navigate to the root directory. You will know you’re in the correct directory if you see folders such as wp-content and wp-admin.
Once there, rename the .htaccess file to .htaccess_stop and reload your website.
Worked? Fantastic. You can now regenerate a new .htaccess file by navigating to Settings » Permalinks in your WP Admin Panel and re-save the settings.
Increase the PHP Memory Limit
Another potential fault could be that the PHP Memory Limit has been reached. To determine whether this is the case, try the follow:
In your root WordPress directory, locate and open the file called wp-config.php
Once opened, add the following line of code within the PHP tags.
And then simply save the file and reload your website.
It’s possible that one (or more) of your plugins could be the cause of the error. A simple way to diagnose this is to deactivate all your plugins and then reactivate them one-by-one to find the culprit.
To do so, connect to your FTP server and navigation to wp-content. Once there, re-name the plugins folder to plugins.stop. Now simply reload your website to see if it’s fixed.
If it has, firstly login to wp-admin and then rename the plugins.stop folder back to plugins. You can then reactivate each plugin one-by-one until the error reappears. You will then know which plugin is at fault.
Re-Upload Core Files
If you have no luck with the above, download a fresh WordPress installation and re-upload the wp-admin and wp-include folders.
It’s a last resort, but it may have to been done.