Django : Error : [u'ManagementForm data is missing or has been tampered with'] after formset is saved
<p>After I press the submit button for a formset being saved, I get this error:
"[u'ManagementForm data is missing or has been tampered with']"</p>

<p>This is the code in my views.py</p>

<pre><code>MarcheFormSet = formset_factory(PrixMarcheForm1, extra=2)
if request.method == "POST":
    formset = MarcheFormSet(request.POST)
    if (formset.is_valid()):
        for form in formset:
            print form
            form.save()
            return redirect("/appartement/ajouter3/")
    else:
        print "nope"
</code></pre>

<p>and my form.html(template being called by views.py)</p>

<pre><code> {% if formset %}
        &lt;form action="" method='POST'&gt;{% csrf_token %}
            {{ formset.management_form }}
            {% for form in formset %}
              {{ form|crispy }}
            {% endfor %}
        &lt;input type='submit' class='btn btn-default' value={{ outcome }}&gt;
        &lt;/form&gt;
    {% endif %}
</code></pre>

<p>And ideas would be greatly appreciated</p>