Problem PHP "require_once"

Hello,

I created a “language.php” file that contains lots of variables that I want to call on all pages of the site.

In the file “header.php” I add “require_once” like this:

<?php require_once('inc/language.php'); ?>

All variables called in the “header.php” file works but not named in the file “footer.php” or any other file elsewhere .

The “print_r” shows me an empty variable.

Is there a solution?

Best regards.