When using Kendo's Upload component when you select a file/files to upload there is a 20% chance that it will upload the same file twice. We switched auto upload off to help, but when you delete one of the dupped files the upload button disappears causing you to delete both of them and then re-upload the file.

Upload Code -

 var w = $("#winFiles").data("kendoWindow");
                w.setOptions({
                    width: $(window).width() - 150,
                    height: $(window).height() - 150
                });
w.center().open();
                $("body").on("click", "#lnkShowUpload", function () { showWinUpload(associationId, typeId) });

function showWinUpload(associationId, typeId) {
var w = $("#winUpload").data("kendoWindow");
    $("#fileUpload").kendoUpload({
async: {
                        saveUrl: `/api/File/?typeId=${typeId}&associationId=${associationId}`,
                        autoUpload: false
                    },
                    validation: {
                        allowedExtensions: ["pdf", "jpg", "img", "png", "gif", "doc", "docx", "xls", "xlsx", "csv", "txt"]
                    }
});
                w.setOptions({
                    height: $(window).height() - 175
                });
w.center().open();
}