Can you please share your Ad unit Id using "Reply Privately to Author" option so that we can test it on our end as well? Experiencing this Error Code 0 means that your ad unit IDs are sending invalid requests to the AdMob server; this can be a result of various factors, such as incorrect ad unit ID usage in code or issues with your AdMob account. Can you confirm us whether you are able to load ads with your Ad unit Id using our sample apps ?
Regards,
Deepika Uragayala
Mobile Ads SDK Team