RE: [google-admob-ads-sdk] "no fill" error – ads not loading even with test & real ad unit ids on real devices

[Mobile Ads SDK Forum Advisor]

Hi,

Thank you for contacting the Mobile Ads SDK Support team.

I'm deleting the thread from the forum as it consists of PII information.

The Error code 3, no fill error means that the ad request was successful, but no ad was returned due to lack of ad inventory. You may check this AdMob Error Codes & Logs for more information on different kinds of errors.

I have executed our Sample project with all the provided IDs in the physical device(realme RMX3241) and I am able to load the ads successfully with all the provided IDs. 

However, upon modifying the package name to com.zymbia.carpm_mechanic, and re-executing the sample project with the same ad unit IDs, ad loading failures occurred. This suggests a potential issue related to the package name.

Upon checking your AdMob account, I observed that the app-ads.txt file has not been configured yet. Although the app-ads.txt file is not absolutely necessary for ads to be displayed, it's still recommended to Set up an app-ads.txt file for your app.

Upon further investigation, this seems to be a serving issue rather than something specific to the Mobile Ads SDK. The best way to get more information about your issue is the AdMob Help Center. You can also utilize the AdMob Communities for additional support. 

Find below your previous response with redacted information.

Hi,
I’ve followed AdMob's official documentation to integrate ads, but I keep getting the error "No fill" for all ad types — including test ads & real ads.

Key Info:

• App Status: Approved in AdMob
• Devices: Tested on multiple real devices
• SDK Version: com.google.android.gms:play-services-ads:24.2.0
• Initialization: MobileAds.initialize() works fine
• Tried:
  • Using real and test Ad Unit IDs
  • Adding test device ID
  • Clearing Play Services data
  • No VPN, no emulator

Test Ad Unit IDs Used:
Banner: ca-app-pub-394xxxxxx4/630xxxx11
Interstitial: ca-app-pub-394xxxxxx544/103xxxxx12
Rewarded: ca-app-pub-39xxxx2544/522xxxxx17

Real Ad Unit IDs Used:
Interstitial: ca-app-pub-8247xxxxx73/286xxxxx88
(Active and created in approved app)

Thanks,
 

Mobile Ads SDK Team

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[2025-05-14 19:55:34Z GMT] This message is in relation to case "ref:!00D1U01174p.!500Ht01qWzWh:ref" (ADR-00305787)