IOS-DFU-Library: Cannot connect with peripheral

Hi, I am developing application and trying to use this library to implement FOTA into it. I am using Swift 3.0 and testing everything on device with iOS 10. Peripheral is based on nRF51822 SoC.

Unfortunatelly library cannot connect with peripheral - stucks on “Connecting”.

I tried running initiator.start() method in different conditions (connected with the device, disconnected with the device, in DFU mode, in normal mode) nothing works. Do you have any idea what am I missing?

bluetooth.manager and bluetooth.connectedPeripheral are not nil.

My implementation:

        let bluetooth = SensorManager.sharedInstance
        self.downloadUpdateFile(uuid: forUUID) { (localFirmwareUrl) in
            if let selectedFirmware = DFUFirmware(urlToZipFile: localFirmwareUrl) {
                let initiator = DFUServiceInitiator(centralManager: bluetooth.manager, target: bluetooth.connectedPeripheral).withFirmwareFile(selectedFirmware)

                initiator.packetReceiptNotificationParameter = 12
                initiator.forceDfu = true
                initiator.logger = self
                initiator.delegate = self
                initiator.progressDelegate = self
                print("START")
                let controller = initiator.start()
            }
        }