{% extends 'global/base.html' %}

{% block content %}
    <div class="container">
        <div class="row">
            <div class="col-md-12">
                <h2>Page not found</h2>
                <p>
                    Sorry! The page you're looking for isn't available.</p>
                <h3>See all <a href="{% url 'core:events' %}">upcoming events</a>.</h3>
                <p><a href="{% url 'core:organize' %}">Find out</a> about
                    organizing a Django Girls workshop in your city.</p>
            </div>
        </div>
    </div>
{% endblock content %}

{% extends 'global/base.html' %}

{% block content %}
    <div class="container">
        <div class="row">
            <div class="col-md-12">
                <h2>Page not found</h2>
                <p>
                    Sorry! The page you're looking for isn't available.</p>
                <h3>See all <a href="{% url 'core:events' %}">upcoming events</a>.</h3>
                <p><a href="{% url 'organize:index' %}">Find out</a> about
                    organizing a Django Girls workshop in your city.</p>
            </div>
        </div>
    </div>
{% endblock content %}

Remove last occurance of core:organize in favour of organize:index
Remove last occurance of core:organize in favour of organize:index
