If during the using of PrestaShop displayed error 500, this error can be based:
- from our WWW server – 500 error page is created by our text and links to the Knowledge Base
- from PrestaShop – page does not contain text, so the browser will show its default error message Error 500
In the first case search for possible causes in our article about the error 500.
In the second case, the error 500 caused by PrestaShop directly in response to a fatal problem, for which an application can not continue. Unfortunately, by default, all errors are masked by PrestaShop and do not show you much information.
The solution is to turn on debug mode in PrestaShop. Open the file config/defines.inc.php and there set the constant _PS_MODE_DEV_ on true value like this (on line 28):
define('_PS_MODE_DEV_', true);
Then instead of a generic error 500 you will see specific error messages.