failed to load ad : 3

Question

I\'m setting an ad to my Android application using DoubleClick and can\'t manage to show the final ad, can someone help me?

When I test an ad by adding ".addTest

Answer 1

For me the reason was that one device, a Xiaomi Mi 9 just was not working anymore and not displaying ads, so I pulled out my tablet and I saw no errors and it was displaying ads in the release.