AdMob: onFailedToReceiveAd(Ad request successful, but no ad returned due to lack of ad inventory.)

Question

There are a couple of other posts on this topic[1], but the answers did not help me.

My problem is a little special: The ads only show up when I am creating the AdView with one Size parameter:

mBanner = new DfpAdView((Activity) getContext(), AdSize.BANNER, _unit);

When I am trying to define fallback sizes, the banner does not show up, but instead logs the error-message (see title of this post):

AdSize[] sizes = new AdSize[]{ AdSize.BANNER, new AdSize(320, 50), new AdSize(320, 75)};
mBanner = new DfpAdView((Activity) getContext(), sizes, _unit);

This isnt working either:

AdSize[] sizes = new AdSize[]{ AdSize.BANNER };
mBanner = new DfpAdView((Activity) getContext(), sizes, _unit);

Any ideas?

[1] onFailedToReceiveAd(Ad request successful, but no ad returned due to lack of ad inventory when using admob with adwhirl

Answer 1

Found the answer: Dfp was not configured to show those sizes.