How to fix a "There has been a critical error on this website." error

The "There has been a critical error on this website." error is similar to the blank white page error seen on older WordPress installations and is most often caused by an error in the WordPress websites code, plugins or themes being used. 

The Below steps will assist you in obtaining more information regarding the actual error and information on how to resolve this and get your website working correctly again. 

How to enable Debug Mode in WordPress.

Enabling debug mode for your WordPress website will allow you to see the full error instead of the generic "There has been a critical error on this website." error.

The below steps will assist you in enabling debug mode via the file manager within your Control panel and via FTP or File Manager. 

File Manager :

• Log into your Direct Admin control panel - these details can be located in the Service Activation email for your hosting package.

• Navigate to File Manager.

• Within the file manager, navigate to the Domains folder then to the domain experiencing the error then to the public_html folder.
• Within the public_html folder you should find the wp-config.php file. 

• Right click on wp-config.php and select Edit. 
• Find the line :

define('WP_DEBUG', false);

and change this to :

define('WP_DEBUG', true);

• Click on Save File.

FTP :

Note - Your FTP credentials can be found within the service activation email that was sent to your when signing up for your WordPress hosting package. 

• Connect to your FTP account using the FTP details found within your service activation email. 
• Once connected to your FTP account, navigate to the public_html folder for your webiste. 
• Download the wp-config.php file to your local PC. 
• Edit the downloaded file using a file editor such as notepad++.
• Find the line :

define('WP_DEBUG', false);

and change this to :

define('WP_DEBUG', true);

• Save the changes.
• Upload the edited wp-config.php file back into the same location using your FTP account and overwrite the existing wp-config.php file. 

Now that debug mode has been enabled, clear your browser cache and browse to the website page you are experiencing the "There has been a critical error on this website." error on. With debug mode enabled any errors on the page will be displayed. Within the displayed errors, look for names of your theme or plugins that you are using. This will indicate that the theme or plugin being mentioned in the error is likely the cause of the error. 

Disable the plugin by follow the steps below :

• Log into your Direct Admin control panel.

• Navigate to WordPress.

• Navigate to WordPress management.

• Navigate to Manage Plugins.
• Here you would be able to disable and enable plugins as required.

Alternatively, you can rename the specific plugin folder to disable it :

• Using the File Manager or your FTP account as before, navigate to your public_html folder.
• Navigate to the wp-content folder. 
• navigate to the plugins folder. 
• rename the specific plugin by adding a number or similar to the beginning of the plugin folder name. 
• This should disable the specific plugin.

NB - Remember to change the line back to false once you have completed your investigation. 

Once you have disabled the plugin causing the error on your website, disable the debug mode and then reload the website in your browser and the website should load as expected. 

You may need to either update the plugin that caused the error or contact the plugin vendor for assistance if you wish to continue making use of the specific plugin.