NullPointerException in PurchaseParams.Builder (Android: java)

This is the Crash Report I got from the Play Console: 

Type

1java.lang.NullPointerException

1Exception java.lang.NullPointerException:
2  at com.revenuecat.purchases.PurchaseParams$Builder.<init> (PurchaseParams.kt)
3  at com.xxxxxxxxxxxx.MainActivity.purchase (MainActivity.java:2103)
4  at com.xxxxxxxxxxxx.MainActivity.lambda$showPaywall$33 (MainActivity.java:2014)
5  at android.view.View.performClick (View.java:7792)
6  at android.widget.TextView.performClick (TextView.java:16112)
7  at android.view.View.performClickInternal (View.java:7769)
8  at android.view.View.access$3800 (View.java:910)
9  at android.view.View$PerformClick.run (View.java:30218)
10  at android.os.Handler.handleCallback (Handler.java:938)
11  at android.os.Handler.dispatchMessage (Handler.java:99)
12  at android.os.Looper.loopOnce (Looper.java:226)
13  at android.os.Looper.loop (Looper.java:313)
14  at android.app.ActivityThread.main (ActivityThread.java:8751)
15  at java.lang.reflect.Method.invoke
16  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:571)
17  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1135)

Here is my code:

1    protected void purchase(Package purchasePackage) {
2        Log.d(TAG_REVENUECAT, "RC: Purchases.getSharedInstance().purchase");
3        Purchases.getSharedInstance().purchase(
4            new PurchaseParams.Builder(this, purchasePackage).build(), new PurchaseCallback() {
5                @Override
6                public void onCompleted(@NonNull StoreTransaction storeTransaction, @NonNull CustomerInfo customerInfo) {
7                    if (customerInfo.getEntitlements().get(PREMIUM_ENTITLEMENT_ID) != null) {
8                        if (Objects.requireNonNull(customerInfo.getEntitlements().get(PREMIUM_ENTITLEMENT_ID)).isActive()) {
9                            // Unlock that great "pro" content
10                            Log.d(TAG_REVENUECAT, "RC: Purchase completed");
11                            AlertDialog.Builder alertBuilder = new AlertDialog.Builder(MainActivity.this);
12                            alertBuilder.setTitle(R.string.thankyou)
13                                .setCancelable(false)
14                                .setPositiveButton(android.R.string.ok, (dialog, id) -> {})
15                                .show();
16                            enablePremium(true);
17                        }
18                    }
19                }
20                @Override
21                public void onError(@NonNull PurchasesError purchasesError, boolean userCancelled) {
22                    // No purchase
23                    Log.e(TAG_REVENUECAT, purchasesError.toString());
24                    Log.d(TAG_REVENUECAT, "Purchase error");
25                    if (!userCancelled) {
26                        showErrorAlert(purchasesError);
27                    }
28                }
29            }
30        );
31    }

About 1% of users affected. I suspect “storeTransaction” or “customerInfo” having null. 

1public void onCompleted(@NonNull StoreTransaction storeTransaction, @NonNull CustomerInfo customerInfo)

Should I check

customerInfo.getEntitlements() != null too?