does not seem to work with file fields about django-dynamic-formset HOT 1 OPEN

I had this same issue. I have a feeling it had/has something to do with me trying to be "fancy" with the styling on my forms, and I don't know what the "correct" fix would be, but the following appears to work (obviously, the jQuery selector will need to change for your own case):

function updateElementIndex(obj) {
    var form_idx=$("#id_link-TOTAL_FORMS").val();
    obj[0].children[0].children[0].id.match(/\d+/g)[0];
    obj.html(obj.html().replace(/(id|name)=(\"[^\"]*)\d+([^\"]*")/g,"$1=$2"+form_idx+"$3"));
    $("#id_link-TOTAL_FORMS").val(parseInt(form_idx) + 1);
}

Then, add it to the added property of your formset call:

$('.individual-form').formset( {
    added: updateElementIndex,
});

from django-dynamic-formset.