KMP: There is no singleton instance. Make sure you configure Purchases before trying to get the default instance.

Hey ​@user-0a9831 ,

This exceptions occurs when SDK methods/actions are called/started without the SDK being in a correct state of initialization.

Can you confirm that calling the configure() of the RevenueCat SDK is only happening once? Having it (without intention) called multiple times in an app’s lifecycle can show these symptoms - you can, before calling it, check if the isConfigure() returns true/false: 

 /**
 * True if `configure` has been called and [sharedInstance] is set
 */
 public val isConfigured: Boolean

More context here

Also, do you have any SDK Debug logs you can share? This helps in trying to see any specific SDK behavior (with the [Purchases] being the prefix that identify them) while your app is running.

Hi ​@guilherme, thanks!

I’m sending now `Purchases.isConfigured` to the error reporter and will see if it’s related. Also added some safeguards to ensure that my init service really runs only once.

Sentry doesn’t show any logs other than the error report, to my awareness, and I’ve not been able to reproduce this.

Sure thing! Let me know when you have any updates here or if you are able to reproduce.

Hello, I received this error for one user from Google Play.

I’m on Unity and just released an update to 20% of userbase.
I’m sure I call configure function because it automatically called on bootstrap screen, then passes to the other screens. This is the snippet of my code:

purchases.SetLogLevel(LogLevel.Warn);
PurchasesConfiguration.Builder builder = PurchasesConfiguration.Builder
  .Init(API_KEY)
  .SetAppUserId(UserSettings.I.timeStamp.ToString());
purchases.Configure(builder.Build());

After finishing onboarding or when player taps premium features, I show paywall which causes the same problem shown in here.

          Caused by kotlin.UninitializedPropertyAccessException: There is no singleton instance. Make sure you configure Purchases before trying to get the default instance. More info here: https://errors.rev.cat/configuring-sdk
       at com.revenuecat.purchases.Purchases$Companion.getSharedInstance(Purchases.kt:1032)
       at com.revenuecat.purchases.ui.revenuecatui.helpers.HelperFunctionsKt.shouldDisplayPaywall(HelperFunctions.kt:48)
       at com.revenuecat.purchases.ui.revenuecatui.activity.PaywallActivityLauncher.launchIfNeeded(PaywallActivityLauncher.kt:171)
       at com.revenuecat.purchasesunity.ui.PaywallTrampolineActivity.launchPaywallIfNeeded(PaywallTrampolineActivity.java:63)
       at com.revenuecat.purchasesunity.ui.PaywallTrampolineActivity.onCreate(PaywallTrampolineActivity.java:50)

Hey ​@cihadturhan,

Thanks for sharing that error details! From what you've shared, it seems that this is happening because of a timing issue where the paywall is being displayed before the RevenueCat SDK has fully initialized on the native Android side.

Even though you're calling Configure() on your bootstrap screen, the configuration process is asynchronous on Android. When the user quickly navigates through onboarding or taps on premium features, the paywall tries to launch, but the native SDK singleton isn't ready yet, causing the UninitializedPropertyAccessException.

Could you try adding that check to ensure the SDK is fully configured before showing the paywall? Or are you doing it already? If so, could you share the code snippet of your implementation?

In case not, here's how:

// After calling Configure
purchases.SetLogLevel(LogLevel.Warn);
PurchasesConfiguration.Builder builder = PurchasesConfiguration.Builder
  .Init(API_KEY)
  .SetAppUserId(UserSettings.I.timeStamp.ToString());
purchases.Configure(builder.Build());

// Later, before showing the paywall
if (!purchases.IsConfigured())
{
    // SDK isn't ready yet - wait or show a loading indicator
    StartCoroutine(WaitForConfigurationAndShowPaywall());
}
else
{
    // Safe to show paywall
    ShowPaywall();
}

IEnumerator WaitForConfigurationAndShowPaywall()
{
    while (!purchases.IsConfigured())
    {
        yield return null; // Wait one frame
    }
    ShowPaywall();
}

As mentioned, the IsConfigured() method will return true once the native SDK is fully initialized and should prevent the crash for those users who are hitting the paywall quickly.

Additionally, to minimize the chance of this happening, you could call Configure() even earlier in your app lifecycle (like in your very first scene's Awake() method) to give the SDK more time to initialize.

In case it helps too, a small delay (not super robust, but in case it helps) before showing the paywall or confirm the IsConfigured could help too.

Could you try that and see how it behaves for you?

​@guilherme Thank you for the pointers.
I have exactly thought this could be problem and checked `IsConfigured` before showing a paywall and called configure again.

var configured = false;
            try
            {
                configured = Purchaser.I.purchases.IsConfigured();
            }
            catch (Exception e)
            {
                Debug.LogError("[RevenueCatUI] Error checking Purchases configuration: " + e);
            }

            if (!configured)
            {
                Debug.Log("[RevenueCatUI] Configuring Purchaser before showing paywall.");
                await UniTask.Yield();
                Purchaser.I.Configure();
            }

I will try your approach, because the solution I tried above didn't work either.

Another reason: some users may not have internet access during configure which may cause fails in configuration?

Ok, I sent an update. I’ll respond in a few days (hopefully with good news).
Thanks!

​@guilherme 

I have updated the app based on your suggestion, but it still happens.

Some important bits:

• This happens very early. It’s generally happens in the first few seconds

• However, I don’t show paywall on game start, so I’m just wondering if any of the android/unity code that automatically tries to show paywall on start.
• Here is the full debug log:

 Caused by kotlin.UninitializedPropertyAccessException: There is no singleton instance. Make sure you configure Purchases before trying to get the default instance. More info here: https://errors.rev.cat/configuring-sdk
       at com.revenuecat.purchases.Purchases$Companion.getSharedInstance(Purchases.kt:1055)
       at com.revenuecat.purchases.ui.revenuecatui.helpers.HelperFunctionsKt.shouldDisplayPaywall(HelperFunctions.kt:48)
       at com.revenuecat.purchases.ui.revenuecatui.activity.PaywallActivityLauncher.launchIfNeeded(PaywallActivityLauncher.kt:171)
       at com.revenuecat.purchasesunity.ui.PaywallTrampolineActivity.launchPaywallIfNeeded(PaywallTrampolineActivity.java:63)
       at com.revenuecat.purchasesunity.ui.PaywallTrampolineActivity.onCreate(PaywallTrampolineActivity.java:50)
       at android.app.Activity.performCreate(Activity.java:8130)
       at android.app.Activity.performCreate(Activity.java:8110)
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1343)
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3781)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3977)
       at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:109)
       at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
       at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2374)
       at android.os.Handler.dispatchMessage(Handler.java:106)
       at android.os.Looper.loopOnce(Looper.java:233)
       at android.os.Looper.loop(Looper.java:344)
       at android.app.ActivityThread.main(ActivityThread.java:8249)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:589)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1071)

Thanks for sharing those extra details/logs and for trying the suggested approaches.

This still seems to point to a timing issue - thinking here is that  PaywallTrampolineActivity is being launched before the SDK completes initialization on the native Android side. But could be tricky to be sure!

Since await UniTask.Yield() and the IsConfigured() checks haven't resolved it, could you try a significantly longer delay to help isolate whether this is purely timing-related? Something like:

if (!configured)
{
    Debug.Log("[RevenueCatUI] Configuring Purchaser before showing paywall.");
    Purchaser.I.Configure();
    await Task.Delay(3000); // 3 second delay to test
}

This is just for testing purposes to see if the issue disappears with a longer wait. If it does, we can work on a more elegant solution from it, so it’s to try and go around it for now.

Also, a few questions to help narrow this down:

1. are you seeing this across multiple devices, or mainly on specific ones? The initial report mentioned A0001, which is a OnePlus One from 2014 right?

2. also, can you reproduce this locally at all, or does it only appear in production/Google Play testing?

3. does this happen on devices with poor/no internet connectivity? You mentioned internet during configure, so that's a good point worth investigating.