angular – currentView.start为null fullcalendar

ORIGINAL EXCEPTION: TypeError: Cannot read property 'clone' of null
ORIGINAL STACKTRACE:
TypeError: Cannot read property 'clone' of null
    at _fetchEventSource (http://localhost:8100/build/js/fullcalendar.js:10703:16)
    at fetchEventSource (http://localhost:8100/build/js/fullcalendar.js:10635:3)
    at fetchEvents (http://localhost:8100/build/js/fullcalendar.js:10629:4)
    at fetchAndRenderEvents (http://localhost:8100/build/js/fullcalendar.js:9789:3)
    at getAndRenderEvents (http://localhost:8100/build/js/fullcalendar.js:9780:4)
    at renderView (http://localhost:8100/build/js/fullcalendar.js:9671:6)
    at initialRender (http://localhost:8100/build/js/fullcalendar.js:9588:3)
    at Calendar_constructor.render (http://localhost:8100/build/js/fullcalendar.js:9552:4)
    at HTMLDivElement.<anonymous> (http://localhost:8100/build/js/fullcalendar.js:53:13)
    at Function.each (http://localhost:8100/build/js/jquery.min.js:2:2813)

在进一步调试时,我发现currentView.start为null,同样设置为rangeStart,这是在fetchEventSource中调用clone的属性.我正在使用defaultview月份.我已经没想完了.请帮帮我.
P.S我正在尝试角度2.我使用的是fullCalendar版本2.7.3. jquery的版本是3.0.0,moment.js的版本是2.13.1.

以下代码导致错误.它是fullCalendar.js的一部分.

function _fetchEventSource(source,callback) {
        var i;
        var fetchers = FC.sourceFetchers;
        var res;

        for (i=0; i<fetchers.length; i++) {
            res = fetchers[i].call(
                t,// this,the Calendar object
                source,rangeStart.clone(),rangeEnd.clone(),options.timezone,callback
            );

            if (res === true) {
                // the fetcher is in charge. made its own async request
                return;
            }
            else if (typeof res == 'object') {
                // the fetcher returned a new source. process it
                _fetchEventSource(res,callback);
                return;
            }
        }
.....