How to solve PHP setlocale in it_IT not working

Sometimes after webserver migration you can loose some configuration especially in regards to language conventions.

In this case I will describe how to solve the missing language issue in PHP and setlocale().

The answer is pretty simple and you can find it here if you use a Debian like system.

Access your shell and edit the following file decommenting the language you want to enable

/etc/locale.gen

After saving the file run:

locale-gen

and the issue is solved.

Remember to restart Apache, NGINX or PHP-FPM based on your webserver configuration.