I found after updating to the latest version of this plugin, that when I try and upload a media file under any of the "Video", "Audio", or "Download" tabs, it will only accept image file types. It looks like the validation for thumbnail uploads have somehow been copied over to the Video, Audio, and Download forms by mistake.

<div id="FileUpload-formVideoItem-container-video_item">
            <div
    id="FileUpload-formVideoItem-video_item"
    class="field-fileupload "
    data-control="fileupload"
    data-unique-id="FileUpload-formVideoItem-video_item"
    data-image-width="100"
    data-image-height="100"
    data-file-types=".jpg,.jpeg,.bmp,.png,.gif,.svg"    data-item-template="FileUpload-formVideoItem-template-video_item">

    <div
        class="image-single attachment-item"
        data-attachment-id=""
        style="width: 100px; height: 100px">

        <!-- Add New Image -->
        <a
            href="nojavascript...;"
            class="uploader-link no-attachment"
            >
            <table><tr><td class="oc-icon-plus"></td></tr></table>
        </a>

        <div class="uploader-progress">
            <div class="progress-bar" role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100"></div>
        </div>
        <div class="uploader-loading"></div>
    </div>