Check that array is not empty

src/model/NotificationPayload.php

@@ -86,7 +86,9 @@ class NotificationPayload
         }
         $instance->latestExpiredReceipt = $request->input('unified_receipt.latest_expired_receipt');
         if ($request->has('unified_receipt.latest_expired_receipt_info')) {
-            $instance->latestExpiredReceiptInfo = Receipt::createFromArray($request->input('unified_receipt.latest_expired_receipt_info')[0]);
+            if (count($request->input('unified_receipt.latest_expired_receipt_info')) > 0) {
+                $instance->latestExpiredReceiptInfo = Receipt::createFromArray($request->input('unified_receipt.latest_expired_receipt_info')[0]);
+            }
         } else {
             $instance->latestExpiredReceiptInfo = null;
         }