error code 500 : internal server error

The 500 Internal Server Error is a very general HTTP status code that means something has gone wrong on the web site's server, but the server could not be more specific on what the exact problem is.

The 500 error is the Web servers way of saying “Something went wrong but I can’t tell you what, sorry.” This is what we call a “server-side” error. That means that there is something wrong with the server who is hosting the website. It is an extremely general error usually caused by configuration issues with the websites programming, PHP or system permissions.

• Check for the resolution:Permissions: Many times you will find that the permission setting on one of your folders is set incorrectly. It could be a simple fix as switching a file/folder permission from 777 to 755 or vice versa. In most cases permission sets of 777 are extremely unsafe and can allow even an amateur hacker to access your files and put malicious code in it. Make sure to check with your hosting provider for specific information about permissions set as some servers have different regulations.
• Incorrectly configured .htaccess: Oftentimes you will receive an internal server error when the htaccess file is configured incorrectly. For PrestaShop purposes, the main culprits of the htaccess errors are “URL Rewrite” settings or Friendly URL enabling. The htaccess syntax is very strict so even one wrong character or command will cause the server to return an Internal Error 500. Make a backup of your htaccess and regenerate the htaccess file either through the back office or by toggling the Enable Friendly URL option.
• Server timeout: Every server has their own timeout setting, which sets the time that any given script can run. If the function or script crosses that limit, you will receive an error 500. You should contact your hosting provider and inquire about changing the limit, at least temporarily.