Bootstrap 3 (as your question is tagged), requires the modal-content
to wrapped in modal-dialog
div..
<div id="responsive" class="modal" tabindex="-1" style="display: none;">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
...
Demo: http://www.bootply.com/123094
The progress-bar may be some to other conflicting element on your page.