Google AdMob released the following statement latelty:
Starting January 23, 2018, we will no longer support Google Mobile Ads (GMA) SDK versions lower than 7.0.0 for Android or iOS.
How can I check in unity which version of Admob SDK I am using?
I found something like that project/projectName/Assets/GoogleMobileAds/Editor/GoogleMobileAdsDependencies.xml
In my project it look like this
<androidPackage spec="com.google.android.gms:play-services-ads:11.2.2">
Here is the last version of sdk https://developers.google.com/admob/android/sdk That's why I think that's it.