This article covers methods to resolve PrestaShop back office error 500.
The error happens when the Back-office is accessed only from Debug mode activated or in production mode activated. The characteristic of this error is that it only occurs in one of the modes and not in both.
Also, this is an error that is occurring ONLY IN PRESTASHOP STORES VERSION 1.7, and that makes it impossible for us to enter the Back-office, showing an error 500 or the page goes blank.
That's why we call it a critical mistake, for leaving the store inoperative.
To fix a HTTP 500 error on PrestaShop online store website:
You can activate your web host's FTP or CPanel error reports in your PrestaShop shop.
1. From PrestaShop v1.4 to v1.5.2
i. Open config/config.inc.php
ii. On line 29, you will find this line: @ini_set('display_errors','off');
iii. Replace it with: @ini_set('display_errors','on');
2. PrestaShop v1.5.3 and later versions (including 1.6 and 1.7)
i. Open config/defines.inc.php
ii. On line 28, you will find this line: define('_PS_MODE_DEV_', false);
iii. Replace it with: define('_PS_MODE_DEV_', true);
Once error reports from the FTP or CPanel are activated, you can browse your store's front or back office to find out what the problem is.
More about Server error 500:
Error 500 means Internal server Error. Whenever a 500 error occurs, the task to return information by the server to the web browser will stop.
Therefore, as we mentioned above, this is a critical error that would leave the website inoperative.
The 500 errors, as we noted above, are internal server errors and their origin may be in a programming code error on any item that is included and related to the request for information returned by the server to the web browser.
Therefore, not all 500 errors come from the same source.