While trying to connect bracelet getting crash

[dsshobhit]

I am trying to integrate SDK in my working project, to get details of wearable devices.
I test providing demo which is completely working fine.
But after integrating this i get crash or an error while creating connection with device from the application.
Here is my code in which i am getting error:

func handleConnectEvent(connectState: DeviceConnectState) {
        switch connectState {
        case .BlePoweredOff://蓝牙没有打开
            print("Bluetooth is not turned on")
        case .BleConnecting://蓝牙连接中
            print("Bluetooth connection")
        case .BleConnectSuccess://蓝牙连接成功
            print("Bluetooth connection is successful")
        case .BleConnectFailed://蓝牙连接失败
            print("Bluetooth connection failed")
        case .BleVerifyPasswordSuccess://验证密码成功,返回上一级
            print("Verify password successfully")
            self.navigationController?.popViewController(animated: true)
        case .BleVerifyPasswordFailure://验证密码失败
            print("Verify password failed")
        }
    }

My complier executes till BleConnectSuccess but after that it automatically crashes.

In working demo next steps going to verifying password but in my integrated code it crashes.

Can anyone please help me out? I did headmarch since last over one week but didn't get any success.
Please suggest.
Thanks in advance.