After update of test project to new build one (second) of the calendars stopped showing appointments
The demo seems to work fine:
Can you specify how to reproduce the issue?
You can also try to record the network traffic using IE and send the NetworkData.xml file to email@example.com for inspection:
Looking at it more I see that the bug is a resource calendar that has actually a problem, it was a second calendar and it does not show any events. Changing it to the Day calendar displays events again.
This bug is fixed now, see also: