title: Getting "footprint is not defined" error message when using timelineMonth view
body: <p>I'm getting the following error message when trying to use the &quot;timelineMonth&quot; default view:</p>
  <p><a href="https://i.stack.imgur.com/kignS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kignS.png" alt="enter image description here" /></a></p>
  <p>I'm using fullCalendar 3.9.0 and Scheduler 1.9.3</p>
  <p>Here is my implementation:
  <a href="https://i.stack.imgur.com/shbD2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/shbD2.png" alt="enter image description here" /></a></p>