Q: After installing 9.3 my iMessage will not work. When I sign in with my Apple ID it just freezes

Greetings Hadjstation,

Thanks for using the Apple Support Communities!

I understand that you are not able to sign in to iMessage on your iPhone after updating to iOS 9.3. We know that situations like this can be very frustrating, but the information in the following article should help you troubleshoot and move forward. 

If you get an error when trying to activate iMessage or FaceTime - Apple Support

Have a great day!