google mobile ads unity crashes app on startup in iOS

Question

I am serving ads using google mobile ads in my Unity game running on iOS and Android. on iOS devices under iOS9, the app crashes on startup. the call stack shows it is crashing in google mobile ads ( [GADApplication runEarlyActivities] ) Anyone had such a problem ?

Answer 1

In case it helps any one, here is what I found:

This crash stopped happening altogether when I built the same app with Unity Pro (I was not using pro before)

dont know why it is related but it is a sure correlation.