Calender Issue

Hi Team,

I have a calender control in my site with multilingual support. There is dropdown filtration in calender based on year and month.
First time it loading fine when I click on the ddl I am not getting its event but the calender control is refreshing and data is disappearing from it.
The control was developed in the older version of Sitefinity and plugged into the newer version. 
I am able to find the event of ddl in older version it is working there.
Could you please suggest what would be the reason behind this.

Mateen