Built-in AdPreloaders don't use back-off when ads fail to load

[vigo2]

[REQUIRED] Step 1: Describe your environment

• Unity version: any
• Google Mobile Ads Unity plugin version: 10.6.0
• Plugin installation method: any
• Platform: any
• Platform OS version: any
• Any specific devices issue occurs on: does not apply
• Mediation ad networks used, and their versions: none

[REQUIRED] Step 2: Describe the problem

The SDK's built-in preloader classes (e.g., InterstitialAdPreloader, RewardedAdPreloader) load ads in a tight loop if an ad fails to load. That makes them unusable in practice, since that behaviour is "strongly discouraged", as the documentation repeatedly states (e.g., https://developers.google.com/admob/unity/rewarded-interstitial#load_the_rewarded_interstitial_ad).

There's no sensible way to configure or add a suitable back-off when using these classes.

Steps to reproduce:

Start preloading with one of these classes and wait for ad loading problems to occur.

Relevant Code:

From our "onAdFailedToPreload()" logging, with two preloader configurations, each with BufferSize = 1:

		Mar 7, 2026 @ 15:36:34.396	rewarded - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:34.394	interstitial - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:33.315	interstitial - failed to preload ad: Too many recently failed requests for ad unit ID: 'ca-app-pub-xxx' You must wait a few seconds before making another ad request.
		Mar 7, 2026 @ 15:36:33.309	rewarded - failed to preload ad: Too many recently failed requests for ad unit ID: 'ca-app-pub-xxx' You must wait a few seconds before making another ad request.
		Mar 7, 2026 @ 15:36:27.395	interstitial - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:27.392	rewarded - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:26.388	rewarded - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:26.386	interstitial - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:25.400	interstitial - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:25.396	rewarded - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:24.514	rewarded - failed to preload ad: Too many recently failed requests for ad unit ID: 'ca-app-pub-xxx' You must wait a few seconds before making another ad request.
		Mar 7, 2026 @ 15:36:24.506	interstitial - failed to preload ad: Too many recently failed requests for ad unit ID: 'ca-app-pub-xxx' You must wait a few seconds before making another ad request.
		Mar 7, 2026 @ 15:36:19.373	rewarded - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:19.368	interstitial - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:18.385	rewarded - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:18.381	interstitial - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:17.501	rewarded - failed to preload ad: Request Error: No ad to show.
		Mar 7, 2026 @ 15:36:17.496	interstitial - failed to preload ad: Request Error: No ad to show.

[NVentimiglia]

Thanks for letting me know, while we look into this can you let me know:

1. which platform (iOS or Android)
2. Can you share some sample code.

Note preloading is still in alpha.

[vigo2]

The log lines above are from an iOS device (iOS-on-macOS).

The relevant code is just:

const string preloadID = "interstitial";

public void Run() {
    InterstitialAdPreloader.Preload(
        preloadID,
        new PreloadConfiguration { AdUnitId = InterstitialAdUnitId, BufferSize = 1 },
        OnAdPreloaded,
        OnAdFailedToPreload
    );
}

void OnAdPreloaded(string id, ResponseInfo responseInfo) {
    Changed?.Invoke();
}

void OnAdFailedToPreload(string id, AdError error) {
    Debug.Log($"{id} - failed to preload ad: {error.GetMessage()}");
}

(InterstitialAdPreloader.DequeueAd(preloadID) is used in the "show ads" code path, but no ad was displayed at that time)

[NVentimiglia]

• Do you call Run only once at the start of the app. We have had issues with people calling Preload multiple times.
• Do you do not show ad in Changed.Invoke()? or is it only UI ?

[vigo2]

Run() is only called once, as part of the initialization. The Changed event is only for UI, so the "watch ad for fun & profit" button appears at an opportune time.

[NVentimiglia]

Thanks for the quick reply, ill check in with my team and let you know.

[NVentimiglia]

Fixed in the next version.