I'm not seeing progress messages, so I'm wondering if the webjars approach might be in conflict with the following:
<!-- shim is needed to support upload progress/abort for HTML5 and non-HTML5 FormData browsers.-->
<!-- use html5-shim.js instead if you just support HTML5 browsers and you need progress event-->
<!-- Note: shim.js MUST BE PLACED BEFORE angular.js and angular-file-upload.js AFTER angular.js-->
<script src="angular-file-upload-shim.min.js"></script>
<script src="angular.min.js"></script>
<script src="angular-file-upload.min.js"></script>
Maybe special instructions for this are needed, if there is indeed a workaround.