Javascript-форум - createDocumentFragment' of null

Доброго времени суток!
Пытаюсь сделать открытие формы в попап окне, но при клике на ссылку в консоли ошибка Uncaught TypeError: Cannot read property 'createDocumentFragment' of null
Помогите, пожалуйста, разобраться. Спасибо.
Форма

<div id="appFastBuy" data-load="<?=SITE_TEMPLATE_PATH?>/images/picLoad.gif">
	<div id="appFastBuyContainer">
		<div class="heading">Купить в один клик <a href="#" class="close closeWindow"></a></div>
		<div class="container" id="fastBuyOpenContainer">
			<div class="column">
				<div id="fastBuyPicture"><a href="#" class="url"><img src="<?=SITE_TEMPLATE_PATH?>/images/picLoad.gif" alt="" class="picture"></a></div>
				<div id="fastBuyName"><a href="<?=$_COOKIE['URI']?>" class="name url"><span class="middle"></span></a></div>
				<div id="fastBuyPrice" class="price"></div>
			</div>
			<div class="column">
				<div class="title">Заполните данные для заказа</div>
				<form action="<?=SITE_DIR?>callback/" id="fastBuyForm" method="GET">
					<input name="id" type="hidden" id="fastBuyFormId" value="">
					<input name="act" type="hidden" id="fastBuyFormAct" value="fastBack">
					<input name="SITE_ID" type="hidden" id="fastBuyFormSiteId" value="<?=SITE_ID?>">
					<div class="formLine"><input name="name" type="text" placeholder="Имя*" value="" id="fastBuyFormName"></div>
					<div class="formLine"><input name="phone" type="text" placeholder="Телефон*" value="" id="fastBuyFormTelephone"></div>
					<div class="formLine"><textarea name="message" cols="30" rows="10" placeholder="Сообщение" id="fastBuyFormMessage"></textarea></div>
					<div class="formLine"><input type="checkbox" name="personalInfoFastBuy" id="personalInfoFastBuy"><label for="personalInfoFastBuy">Я согласен на <a href="/personal-info/" class="pilink">обработку персональных данных.</a>*</label></div>
					<div class="formLine"><a href="#" id="fastBuyFormSubmit"><img src="<?=SITE_TEMPLATE_PATH?>/images/incart.png" alt="Купить в один клик"> Купить в один клик</a></div>
				</form>
			</div>
		</div>
		<div id="fastBuyResult">
			<div id="fastBuyResultTitle"></div>
			<div id="fastBuyResultMessage"></div>
			<!--<a href="" id="fastBuyResultClose" class="closeWindow">Закрыть окно</a>-->
            <span id="fastBuyResultClose" class="closeWindow">Закрыть окно</span>
        </div>		
	</div>
</div>

Ссылка

<a href="#" class="fastBack label changeID<?if(empty($arResult["PRICE"]) || $arResult["CATALOG_AVAILABLE"] != "Y"):?> disabled<?endif;?>" data-id="<?=$arResult["ID"]?>"><?=GetMessage("FASTBACK_LABEL")?>1 клик</a>

Скрипт

var fastBuyOpen = false;

$(document).load("ready", function(event) {
    console.log(fastBuyOpen);
    /*var $body = $("body").removeClass("loading"); // cache body
    var $window = $(window);*/

    var openFastBack = function (event) {

        var $this = $(this);

        if ($this.hasClass("disabled")) {

            var $appFastBuy = $("#appFastBuy");
            var $foundation = $("#foundation").addClass("blurred");

            $("#fastBuyOpenContainer").show();
            $("#fastBuyResult").hide();

            $("#fastBuyForm").find('input[type="text"], textarea').val("");

            var productID = $this.data("id");

            $this.addClass("loading");

            var gObj = {
                id: productID,
                act: "getFastBuy"
            };
            console.log(gObj);
            $.getJSON(ajaxPath, gObj).done(function (jData) {

                $this.removeClass("loading");
                $appFastBuy.find("#fastBuyPicture .url, #fastBuyName .url").attr("href", jData[0]["DETAIL_PAGE_URL"]);
                $appFastBuy.find("#fastBuyPicture .picture").attr("src", $appFastBuy.data("load"));
                $appFastBuy.find("#fastBuyPrice").html(jData[0]["PRICE"]["PRICE_FORMATED"]);
                $appFastBuy.find("#fastBuyName .middle").html(jData[0]["NAME"]);
                $appFastBuy.find("#fastBuyFormId").val(jData[0]["ID"]);
                $appFastBuy.find(".markerContainer").remove();

                if (jData[0]["MARKER"] != undefined) {

                    $appFastBuy.find("#fastBuyPicture").prepend(
                        $("<div>").addClass("markerContainer")
                            .append(
                                jData[0]["MARKER"]
                            )
                    );
                }


                $appFastBuy.show();

                loadingPictureControl(jData[0]["PICTURE"]["src"], function () {
                    $appFastBuy.find("#fastBuyPicture .picture").attr("src", jData[0]["PICTURE"]["src"]);
                });

            }).fail(function (jqxhr, textStatus, error) {

                $.get(ajaxPath, gObj).done(function (Data) {
                    console.log(Data)
                });

                $this.removeClass("loading")
                    .addClass("error");

                console.error(
                    "Request Failed: " + textStatus + ", " + error
                );

            });

            fastBuyOpen = true;
        }

        return event.preventDefault();
    };

    var sendFastBack = function(event){

        var $this = $(this).addClass("loading");
        var $fastBuyForm = $("#fastBuyForm");
        var $fastBuyFormName = $fastBuyForm.find("#fastBuyFormName").removeClass("error");
        var $fastBuyFormTelephone = $fastBuyForm.find("#fastBuyFormTelephone").removeClass("error");

        if($fastBuyFormName.val() == ""){
            $fastBuyFormName.addClass("error");
        }

        if($fastBuyFormTelephone.val() == ""){
            $fastBuyFormTelephone.addClass("error");
        }

        var $personalInfo = $fastBuyForm.find("#personalInfoFastBuy");
        if(!$personalInfo.prop("checked")){
            $personalInfo.addClass("error");
        }

        if($fastBuyFormName.val() != "" && $fastBuyFormTelephone.val() !="" && $personalInfo.prop("checked")){

            $.getJSON(ajaxPath + "?" + $fastBuyForm.serialize()).done(function(jData){

                //metrica
                if(typeof globalSettings != "undefined" && typeof globalSettings["TEMPLATE_METRICA_FAST_BUY"] != "undefined" && typeof globalSettings["TEMPLATE_METRICA_ID"] != "undefined"){
                    window["yaCounter" + globalSettings["TEMPLATE_METRICA_ID"]].reachGoal(globalSettings["TEMPLATE_METRICA_FAST_BUY"]);
                }

                $("#fastBuyResultTitle").html(jData["heading"]);
                $("#fastBuyResultMessage").html(jData["message"]);

                $("#fastBuyOpenContainer").hide();
                $("#fastBuyResult").show();

                $this.removeClass("loading");

            }).fail(function(jqxhr, textStatus, error){

                $this.removeClass("loading").addClass("error");

                console.error(
                    "Request Failed: " + textStatus + ", " + error
                );

            });

        }else{
            $this.removeClass("loading");
        }

        return event.preventDefault();
    };

    var closeFastBack = function (event) {
        var $appFastBuy = $("#appFastBuy").hide();
        var $foundation = $("#foundation").removeClass("blurred");
        return event.preventDefault();
    };

    $(document).on("click", ".fastBack", openFastBack);
    $(document).on("click", "#appFastBuy .closeWindow", closeFastBack);
});