In case you have seen something similar to the picture above on your website before or you see it sometime in the future, you need to know that you were/are experiencing a 500 internal server error.
An internal server error or 500 internal server error is general HTTP status code which indicates that the server is having issues performing its functions without providing any specific details on the issue itself. To get any further details and specifics regarding what's wrong with the server the site owner would be required to do some troubleshooting.
Knowing the true cause of an internal server error is not a straight forward process as it requires a number of checking ins on different files and sections of the website backend. Sometimes it gets as far as the webmaster having to call the host to submit an error report.
As hard as it is to outrightly determine the cause of an internal server error there are certain common factors that you can check for if you ever come across this error on your website.
The first thing to do is to check the PHP and Apache error logs on your server. Thought this might not necessarily give you the full details of the error but the report generated in the log can give you better insight on what your next step should be.
You can check the cpanel provided by your host for the error logs, Since different hosts have different interfaces the path to the error logs might be different, it is best to contact your host on how to locate your error logs or ask someone who is already familiar with the interface.
PHP Script Timeout
A PHP Script timeout happens whenever the server is making external connections with a long running PHP Script, one of the scripts running on the server at that time may end up exceeding the set runtime on the server, this will generate a 500 internal server error.
Corrupt .htaccess file
Any compromise in your sites .htaccess file could generate an internal server error. Since .htaccess is responsible for running the web server, any discrepancies in the text file would affect the server functions and generate an error.
Issue with Plugin
A faulty plugin could also be the reason for the error. If a plugin is not running correctly it could end up affecting the performance of the server hence, the error.
Since it's usually difficult to tell what's causing an internal server error. The following are the steps to take if you ever come across error 500 on your website
Renaming the .htaccess File
To check for a corrupted .htaccess file, simply rename your former .htaccess file and create a new one.
To rename your .htaccess file you need to login to your website with a FTP client. A software like FileZilla can do the job.
To locate the .htaccess file, just check the root directory where you can find wp-admin, wp-includes and wp-content.
Once you find the file you can rename it into whatever you want, your website will be dispossessed of a .htaccess file at that point.
Sometimes the .htaccess file may not be visible at first, In this case search around for the option to display hidden files in your FTP client and you'll be alright.
After renaming the file head over to the WordPress backend go to
Settings > Permalinks
Click on Save Changes and you'll have a new .htaccess file. Now we can reload our website to see the results. This should fix the error, but in case it doesn't move to the next step.
**Increasing PHP Memory Limit **
To know if the error is as a result of a PHP Script going haywire,
firstly in your root directory, locate the wp-config.php file and download it to your computer to make some changes.
After downloading open the file and add this line of code after the PHP opening tag
define('WP_MEMORY_LIMIT', '64M');
Save the file and upload it back to your directory overriding the former one.
If the issue is still not resolved, then the next step is in order
Deactivation and Reactivation of all Plugins
This step requires you to firstly deactivate all functioning plugins on your website. You can do this by deactivating individually by clicking the deactivate link in the image below, the other way to do this is by applying the deactivate in bulk, you can get this done by marking all plugins, click on the select box beside "Plugins" to do that, then choose "Deactivate" from the dropdown that says "Bulk Actions" in the upper left and clicking the Apply button beside it
If the error disappear after deactivating all plugins, then a faulty plugin is the cause of the issue, in this case you need to start reactivating each plugin one-by-one to be able to identify the culprit among them.
After reactivating one plugin, reload your website if the error reappears after a certain plugin has been reactivated, then that plugin is the cause of the error, delete the plugin and find a better alternative.
If any of the solutions provided above does not solve the issue, you need to contact your host for help.