get_template_part containing custom fields

Hello,

I want to achieve the following. I’m in need of a couple of custom fields on my 404.php so what I did was the following:

I emptied my 404, made an 404-content.php which I gave the template name 404 and put some custom fields in there.

Then I added the following line of code in my 404.php:

<?php get_template_part( '404-content' ); //don't put extension(.php) ?>

But the custom fields don’t seem to work and I have now idea why?