Bootstrap modal not open again

I have a two bootstrap modal in update panel for for e.g

 

i used the fullcalendar for manage event in my task i click on the (particular time slot) open my first modal popup after save the event.

 

The event dislay in fullcalendar i will provide edit functionality if user click on event open second popup in that popup i was put edit button, when user click on it open my first popup

 

But the problem is first time open the popup when i click on it edit button but when i click second time does not open

 

Inspect element display modal-backdrop fade show..