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What is a 500 error?


What is a 500 error?

This is a quite common and generalized error every time the server encounters a problem with PHP. PHP is a programming language that PrestaShop uses.

There are several types of 500 errors

A - Those of PrestaShop that look like this:

To identify the error, you must activate the Debug mode, you have 2 solutions either through the FTP or through your store.


1 - Activate the Debug mode through your FTP.

If you cannot activate the Debug mode from your store, connect to your server with your FTP software, edit the file in the /config/ folder and replace the following line

define('_PS_MODE_DEV_', false);
define('_PS_MODE_DEV_', true);

then save your file.


2 - Activate the Debug mode

For that :

  • Click in the menu on Advanced settings
  • Then on "Performance"
  • Set "Debug Mode" to Yes


3 - Read the error message

Often the message is quite explicit for Prestashop errors under the display PrestashopException, for example in the picture below, the message tells you "Link to database cannot be established" it means that the server can not make the link with your database.



4 - Correct the error

To correct the error, there are 2 solutions, either you have a minimum of technical knowledge that allows you to make the correction yourself, or you will have to call a specialized provider:

  • PrestaShop support
  • your web agency
  • a freelancer

B - The one of the server

It may look like a blank page or a 500 error page different from the one in PrestaShop.

Generally you need a minimum of technical skills to identify the error.


The procedure is in two steps:

1 - Consult the PHP logs of the server

If you can access this file, normally the error will be displayed at the bottom and you will have to correct it
If you can't access this file, activate the debug mode (as explained above)

2 - If you activate the debug mode.

You will have 2 possibilities :

either the error is displayed and you can correct it if you have the necessary skills.
or the error is not visible, in which case you will have to investigate.

In both cases we advise you to call a technical service provider.