Starting with this version some advanced security features such as UTM, IPS, and AppSecure require licenses. Stick to the old version if you want to use these features for free.
Juniper Firefly Perimeter VMware Image
Release 12.1X47-D20.7, March 2015
Also you can try a 30 days evaluation license in E419777401.txt
I recommends Buy premimum account for High speed+parallel downloads!