NFCCore problems - class "NFTechnologyEvent" not loaded or does not exist

Hi,

I'm developing an app for communicate through NFC.

I've:

- setted "NFC Tag Reading" capability for app on Apple project page.


- use iPhone 7 and iOS 11.4.1 (the last iOS version)


- added in entitlement file

<key>com.apple.developer.nfc.readersession.formats</key>

<array>

<string>NDEF</string>

</array>


- added in info.plist file

<key>NFCReaderUsageDescription</key>

<string>NFC Read</string>


- write a simple ViewController to manage NFC Communication

var nfcSession: NFCNDEFReaderSession!
     func startScanning(){
       nfcSession = NFCNDEFReaderSession(delegate: self, queue: DispatchQueue.main, invalidateAfterFirstRead: false)
       nfcSession.alertMessage = "You can hold you NFC-tag to the back-top of your iPhone"
       nfcSession.begin()
     }
     override func viewWillAppear(_ animated: Bool) {
          super.viewWillAppear(animated)
          startScanning()
     }
     extension NfcReaderViewController : NFCNDEFReaderSessionDelegate {func readerSession(_ session: NFCNDEFReaderSession, didInvalidateWithError error: Error) { 
          print("Error reading NFC: \(error.localizedDescription)") 
          //session.invalidate() 
          //self.startScanning() 
     } 
     func readerSession(_ session: NFCNDEFReaderSession, didDetectNDEFs messages: [NFCNDEFMessage]) { 
          //Never called 
     }
}


However, when the phone is near to NFC tag that send NDEF messages, I obtain always this error:

connection to service named com.apple.nfcd.service.corenfc: Exception caught during decoding of received message, dropping incoming message.
Exception: Exception while decoding argument 0 (#2 of invocation):
Exception: decodeObjectForKey: class "NFTechnologyEvent" not loaded or does not exist


Moreover I try to scan NFC tags through more app downloaded from the store, and also in them I obtain a similar error.

There is a reason?

Apple documentation is poor and doesn't explain nothing on errors received.


Thank you!