Why does version 2.1 stop generating define when the specs are passed

Hi,

I am trying to generate Define in version 2.1, For some reason the application stops working and throws a message "

Uh oh, a serious error has occurred..."

 and forces to restart the application. If the same specs are passed into version 2.0 it runs fine.

Can anyone please help me in identifying the reason for this.

Thanks!!!