Schedule component can't be run

[amenooooo1]

I copied and pasted the codes of the Schedule component from PrimeFaces.org for version 12.0.0 as it is but I couldn't have any successful run, I have also tried other versions and I get the same error which is "Cannot invoke "org.primefaces.model.ScheduleModel.isEventLimit()" because the return value of "org.primefaces.component.schedule.Schedule.getValue()" is null". Could you please help me with that?

My environment:

JSF 2.2.4
PrimeFaces 12.0.0
JavaSE 18