Same Date not occurs Events

hi
I want that no two or more events will occurs on same dates ,but when i am using this functionality i face javascript errors ,and drag features come ,previous events not shown ,What will be problem while i am using v2.3 Please provide me soulution ,
Thanks in advances
Vijay

Hello,

Please check Collisions extension page.
If something is failing for you try replacing collision source file with the version available on the Known issues page.

Best regards,
Ilya