
This fixes the width (no clue how to fix the height, but there is a vertical scrollbar and this makes the whole thing resizable, too):
// src\WebPlayer\wwwroot\player.js, LINE 90
function showMenu(title, options, allowCancel) {
$("#dialogOptions").empty();
$.each(options, function (key, value) {
$("#dialogOptions").append(
$("<option/>").attr("value", key).text(value)
);
});
$("#dialogCaption").html(title);
var dialogOptions = {
modal: true,
autoOpen: false,
resizable: true, // I am new (and not actually necessary)!
width: 'auto', // I am new!
buttons: [{
text: "Select",
click: function () { dialogSelect(); }
}]
};

This fixes the width (no clue how to fix the height, but there is a vertical scrollbar and this makes the whole thing resizable, too):