Correcting a 500 error

The 500 error is a problem that can occur from time to time, especially when updating the theme or modules of your website. This article presents the main causes and solutions to 500 errors.

1. Permission error

In many cases, you will find that the file permissions are not set correctly.

To correct this error, simply set the permission of a file or folder to 755 instead of 777 (or vice versa).

As a general rule, 777 permissions are incredibly poorly protected and even an amateur hacker can enter your files and introduce malicious software.

Think about hosting: check the specific permission characteristics with your host, as some web servers use different rules.

2. Incorrect configuration of the .htaccess file

Internal server problems are often caused by a poorly configured .htaccess file.

In the case of PrestaShop, problems are generally related to URL rewriting options and the activation of "friendly URLs".

The syntax of a .htaccess file is very strict and even a character or a command that is incorrect could cause an internal server error 500. Therefore, indicating "NO" in the "friendly URLs" option could be a solution (do not forget to save your changes).

We recommend that you save your .htaccess file and restore it from the back office or disable "friendly URLs".

3. Time out

Each web server has its own waiting time, which determines the execution time of a script. If the function or script exceeds this time limit, you will receive an error 500.

Here are the PrestaShop scripts that may take too long to load:

• Importation of CSV files.
• Backup files.
• Loading translations.
• Imports/exports.
• Regeneration of thumbnails.

Often, the server's time limit is 30 seconds, which is insufficient for these scripts.

In this case, you should contact your host and ask them to modify this parameter (at least temporarily).

In the case of importing CSV files, the error 500 can sometimes be due to exceeding the maximum execution time, and not all hosting services allow you to modify this parameter.

4. Obsolete modules

It is possible that when you update your store, for example if you switch from version 1.7 to version 8, you encounter obsolete modules or incompatible with this new version of PrestaShop.

This can generate error 500. In this case, you should review all the addons you have installed, or at least those that are available in a more recent version.

We recommend that you always have at hand (or saved in your favorites) the official PrestaShop Marketplace page, where you can obtain recent modules.

5. Incompatible modules, themes or extensions

Whether you are using PrestaShop or another CMS (Wordpress, Shopify), installing plugins, themes or extensions on non-adapted content management systems can trigger conflicts and create an internal server error.

If the error 500 has occurred following the installation of new modules, please consult the article Error 500 after installing or updating a module for the steps to follow.

What should I do if the error 500 persists on my site or web page after these checks?

If these solutions do not resolve the problem, we offer Advanced Technical Support that includes a complete diagnosis and personalized resolution of your problem. If you have any questions or would like to proceed with this option, please do not hesitate to contact us.