Angular7 FullCalendar错误：无法读取未定义的属性“ length”

Question

I am trying out FullCalendar version 4.3 on a clean Angular 7.2.0 application. I am following this official guide . When I load a simple empty calendar, it works fine. As soon as I add any events AND the event should be displayed, it throws an error without displaying the event.

full calendar with events (copied from documentation):

<full-calendar
  defaultView="dayGridMonth"
  [plugins]="calendarPlugins"
  [weekends]="false"
  [events]="[
    { title: 'event 1', date: '2019-08-06' },
    { title: 'event 2', date: '2019-08-07' }
  ]"
></full-calendar>

Error:

ERROR TypeError: Cannot read property 'length' of undefined
    at DayGridView.push../node_modules/@fullcalendar/core/main.esm.js.View.computeEventDraggable (main.esm.js:7575)
    at DayGridEventRenderer.push../node_modules/@fullcalendar/daygrid/main.esm.js.SimpleDayGridEventRenderer.renderSegHtml (main.esm.js:218)
    at DayGridEventRenderer.push../node_modules/@fullcalendar/core/main.esm.js.FgEventRenderer.renderSegEls (main.esm.js:7799)
    at DayGridEventRenderer.push../node_modules/@fullcalendar/core/main.esm.js.FgEventRenderer.renderSegs (main.esm.js:7763)
    at DayGrid.res [as renderFgEvents] (main.esm.js:3183)
    at DayGrid.push../node_modules/@fullcalendar/daygrid/main.esm.js.DayGrid.render (main.esm.js:742)
    at DayGrid.push../node_modules/@fullcalendar/core/main.esm.js.Component.receiveProps (main.esm.js:3881)
    at SimpleDayGrid.push../node_modules/@fullcalendar/daygrid/main.esm.js.SimpleDayGrid.render (main.esm.js:1518)
    at SimpleDayGrid.push../node_modules/@fullcalendar/core/main.esm.js.Component.receiveProps (main.esm.js:3881)
    at DayGridView.push../node_modules/@fullcalendar/daygrid/main.esm.js.DayGridView.render (main.esm.js:1584)

Answer 1

I found this example angular project on github which works fine. I recreated the project from scatch, updating the FullCalendar version to 4.3.0 (latest) without any problems. I can't figure out what went wrong in the original app, however if anyone's having trouble getting it to work, the example project will help.