PKPaymentAuthorizationViewController(paymentRequest: requestObject) is returning nil - ios

Question

I am facing a problem in initilizing PKPaymentAuthorizationViewController returning nil in one of the device.
The device region is set to UK and I have added a UK issued card in the Apple Wallet.
The PKPaymentRequest is configured as following:
let request = PKPaymentRequest()
request.merchantIdentifier = "mymerchantid"
request.supportedNetworks = [PKPaymentNetworkVisa, PKPaymentNetworkMasterCard, PKPaymentNetworkAmex]
request.merchantCapabilities = PKMerchantCapability.Capability3DS
request.countryCode = "US"
request.currencyCode = "USD"
let price: <NSDecimalNumber>
let item : PKPaymentSummaryItem = PKPaymentSummaryItem(label: "amount", amount: price, type: .Pending)
request.paymentSummaryItems = [
item
]
let paymentAuthorizationVC = PKPaymentAuthorizationViewController(paymentRequest: request) // Returning Nil
if PKPaymentAuthorizationViewController.canMakePaymentsUsingNetworks(SupportedPaymentNetworks) // Returns true
Device: iPhone 6
OS: 10.2.2
Note: Same Card is onboared in another device for the same App its working fine.
Tried as mentioned in the below link and few other blogs- no luck
Apple pay PKPaymentauthorizationViewController always returning nil when loaded with Payment request
Looking for suggestions.

Answer 1

I had this same problem and the cause was using a Discover card for testing when it's not included as a supported payment network. Make sure that you are passing in all the credit card types that your user base will possibly use.
Try changing this line:
request.supportedNetworks = [PKPaymentNetworkVisa, PKPaymentNetworkMasterCard, PKPaymentNetworkAmex]
To the following:
request.supportedNetworks = [PKPaymentNetworkVisa, PKPaymentNetworkMasterCard, PKPaymentNetworkAmex, PKPaymentNetwork.discover]
In Swift3, The declaration for PKPaymentAuthorizationViewController init() is not defined as optional, even though it does return nil when it fails.