UI dialog problem

Hi experts,

In Adobe CC version of InDesign, the Java Script UI has a problem, if active the ui, it will cause script jump out InDesign (if some folders are open) after run the script.

    var
        w = new Window("dialog","UI_Stub", undefined, {closeButton: false}), 
        p = w.add("panel"),
            mLine = p.add("group"),
                mStat1 = mLine.add("statictext", undefined, "Leave left: "),
                mEdit1 = mLine.add("edittext", undefined, ""),
                mStat2 = mLine.add("statictext", undefined, " character(s)"),
        mB = w.add("group");
        mB.add ('button', undefined, "OK", {name: "OK"});  
        mB.add ('button', undefined, "Cancel", {name: "Cancel"}); 
        mLine.alignChildren = "left";
        mEdit1.characters = 3;
        mB.spacing = 50;
        mEdit1.active = true;
        if (w.show() == 1);

I active the mEdit1

Thanks

John