LoadAdError(code: 3, domain: com.google.android.gms.ads, message: No ad config... when trying to load BannerAd in release mode

Question

I have an app with the ads, when I run my app in debug mode with the test ad unit, everything works fine. However, when I run the app in release mode with the real ad unit from AdMob, I have an error

LoadAdError(code: 3, domain: com.google.android.gms.ads, message: No ad config., responseInfo: ResponseInfo(responseId: null, mediationAdapterClassName: , adapterResponses: []))

I'm having this for almost two months, please help me resolve it.

Here is a link for a GitHub issue I've opened, refer to it for a more detailed explanation.

Answer 1

Add your Phone as test device in Google Admob over at the Settings. Then it should work! When releasing to play store make sure to state that your app is using Ads in the console

Answer 2

I've found the cause of the problem and the solution. The fact that the app was not signed was the cause of LoadAdError(code: 3, domain: com.google.android.gms.ads, message: No ad config., responseInfo: ResponseInfo(responseId: null, mediationAdapterClassName: , adapterResponses: []))

Signing the app have solved my issue.