Как избавится от предупреждения: com.google.ads.m: can’t find referenced class com.google.ads.internal.state.AdState

Для истории такое сообщение пришло к нам с AdMob SDK 6.2.1 (for Android):

Proguard returned with error code 1. See console

Warning: com.google.ads.m: can't find referenced class com.google.ads.internal.state.AdState

Warning: com.google.ads.m: can't find referenced class com.google.ads.internal.state.AdState

You should check if you need to specify additional program jars.

Warning: there were 2 unresolved references to classes or interfaces.

You may need to specify additional library jars (using '-libraryjars').

java.io.IOException: Please correct the above warnings first.

at proguard.Initializer.execute(Initializer.java:321)

at proguard.ProGuard.initialize(ProGuard.java:211)

at proguard.ProGuard.execute(ProGuard.java:86)

at proguard.ProGuard.main(ProGuard.java:492)

Страшно? 

А лечится довольно просто, добавьте строку в proguard.cfg файл Вашего проекта:

-dontwarn com.google.ads.**