Notification does not send when the assignment rule is changed empty to assigned

[Jyoti Ranjan Se]

Hi All,

I have notication for a custum application which is trigger by event . i wrote a business rule for it when the assignment group changes it sends the notifiaction but it is not sending when the assignment rule is assigned from empty.

Can you please help on this.I have attached the screenshot of business rule when to run condition. 

[Sanjana8]

Try making it as a before business rule