android facebook facebook-ads-api facebook-audience-network

How to resolve Error = 1001 “No Fill” using Facebook Audience Network in android

I have an Android version of my app and integrated FAN into my Application.
It worked for some months but now it’s displaying “NO FILL

Error Code=**1001 "No fill"** 
UserInfo={NSLocalizedDescription=**No fill**,
FBAdErrorDetailKey={ msg = "**No fill**"}}

And no FAN ad is shown. If I put a testing ID then it’s displaying, but only on my device, not for another device.

How to resolve this problem “No Fill”?

compile ''

Mentioned in build.gradle
I’ve seen many questions regarding this but unable to find an answer.

I’ve already seen below links:

  1. Facebook AudienceNetwork loaded failure: No fill, Error Message “No fill”, what is the reason about FaceBook android Advertise?

  2. facebook audience network testing on test flight No Fill

  3. Audience Network iOS Ads Suddenly Become “No Fill”

  4. Facebook Audience Network returns “No fill”

  5. Testing Audience Network Implementation