In some cases when trying to integrate mobile ads into your application, you may see an error stating that you app has been disabled (DISABLED_APP, error code 400, or similar).
Until recently, the most common reason for disabling an app with ads was the missing tax information, normally applicable to newly created developer accounts, where you didn't have a chance to complete that info yet. Without it, all submitted apps were disabled for ads. With the most recent change, ad impressions will be generated even with an incomplete tax status, however you will not be paid your ad earnings until your tax info is complete. Therefore, the first step would be to check that you have filled the tax information in your dev portal account, and if you’ve done that and got approved, this point does not apply to you.
The ads in your app could have been disabled due to COPPA violation. COPPA stands for Children's Online Privacy Protection Act, and if you are targeting your app to users under 13 years of age, and because we don’t display ads to those users, ads could have been disabled. In that case ads will not appear even in test mode. To resolve that, either select 'No' for the question 'Is your app directed primarily at kids under age 13?' under the 'Content Rating' tab in the application submission process if your app is not directed at kids, or remove mobile ads if kids below 13 are your audience. If your app got disabled due to COPPA violation, you will have to contact us to re-evaluate the app and re-enable it, even after you have marked it as targeting users above 13 years of age.
Mobile ads will be served only to users in the U.S., U.K., Germany, France, Spain, Italy and Japan. Your app itself will still function properly in any geographic region, but ads will be displayed only in the countries mentioned above. If you want ads to be displayed in more countries, you may implement some logic in onAdFailedToLoad() of your AdListener that will load an ad from an alternative network: https://developer.amazon.com/public/apis/earn/mobile-ads/docs/with-other-sdks This applies only to ads in live mode (you should still be able to see ads in test mode in any country, assuming there is no COPPA violation)
A NO_FILL error can occur even with test ads enabled if the app is trying to load an auto-sized ad in a container whose dimensions are WRAP_CONTENT x WRAP_CONTENT. This will cause an Auto Ad Size failure and result in no ads being returned. Generally, if this is a screen-width ad then our recommendation for this case would be to change the AdLayout's layout params dimensions to be MATCH_PARENT x WRAP_CONTENT. Auto Ad Size should not be used if a specific ad size is required. Instructions and guidelines for ad sizes can be found here: https://developer.amazon.com/public/apis/earn/mobile-ads/android/docs/concepts#Ad%20Sizes.
If none of these applies, and you still experience issues or have any questions, please use the Contact Us link in your Distribution Portal account: https://developer.amazon.com/help/contact-us.html so we can look into your individual case further.