Thanks for reaching out!
The following error code indicates that the adapter file for the network is missing, renamed or in the wrong place.
MoPubErrorCode: Unable to find Native Network or Custom Event adapter.
For Android, the adapters should be placed in the com.mopub.mobileads folder for all formats except native. For native, they should be placed in the com.mopub.nativeads folder. Full instructions are detailed here.
For the custom event class field in the MoPub UI, you will want to enter the location of the adapter. For example, a publisher mediating Unity Ads would enter the following into the custom event class field of the MoPub UI: com.mopub.mobileads.UnityRewardedVideo
For iOS, the adapter files can be found in the Ad Network Support folder. Full integration details are outlined here.
For the custom event class field in the MoPub UI, you will want to enter the name of the adapter. For example, a publisher using Unity Ads Rewarded Video would enter the following into the custom event class field of the UI: UnityAdsRewardedVideoCustomEvent
For Unity Engine, you will need to follow the instructions outlined in our Unity documentation to include the adapter file. This entails adding the correct .unitypackage file to your project.
For the custom event class field in the MoPub UI, follow the instructions outlined above for iOS and Android.
If you are still having trouble, please reach out to the MoPub Support Team directly at firstname.lastname@example.org. Please make sure to include the full device logs from your testing, your ad unit ID and the email address associated with your account in your email.