Django: 'current_tags' is not a valid tag library

I have a small Django project I received from a friend. The code works perfectly on his system. However, on my system I get the following error message when running the server:

TemplateSyntaxError at /

'current_tags' is not a valid tag library: Template library current_tags not found, tried django.templatetags.current_tags

The problem is with a line in an html file:

{% load current_tags %}

This exact same code works on his system with no errors. What could that be?