[Fixed]-Django CMS Placeholder Within Template Block Not Displaying

I was able to resolve this using the following modifications.

base.html:

<!-- Main Content -->
{% placeholder content or %}
<div class="container">
    <div class="row">
        <div class="col-lg-8 col-lg-offset-2 col-md-10 col-md-offset-1">
            {% block content %}{% endblock %}
        </div>
    </div>
</div>
<hr>
{% endplaceholder %}  

content.html:

{% extends "base.html" %}
{% load cms_tags %}

{% block content %}
{% endblock content %}