This is because the Page is not set up to display Content while in List View. To change this navigate to:
  1. onMessage > Website > Site Name  > Find the Calendar Page (usually a landing page)
  2. Click the Editing Wrench, and click Edit Page Content
  3. Scroll down to the region titled Page Content Region that has a "Calendar Grid"  content block in it
  4. Just above that block is a button that allows you to select List View or Grid View., click on List view
  5. Within the Page Content Region there is  no Content Block displayed
  6. Drag the Event List Block from the left column, and drop it onto the Page Content Region for List View
  7. Click Apply Changes in the bottom right