StreamSocket _connection = AsyncCreateConnection(); // In constructor
private async void receive(){
DataReader reader = new DataReader(_connection.InputStream);
DataWriter writer = new DataWriter(_connection.OutputStream);
try
        {
            reader.InputStreamOptions = InputStreamOptions.Partial;
            uint sizeFieldCount = await reader.LoadAsync(sizeof(uint)); // <<--  Explosion
            if (sizeFieldCount != sizeof(uint))
            {
                return;
            }
            // Read the string.
            uint stringLength = reader.ReadUInt32();
            uint actualStringLength = await reader.LoadAsync(stringLength);
            if (stringLength != actualStringLength)
            {
                return;
            }
            Debug.WriteLine(reader.ReadString(actualStringLength));
        }
        catch (Exception exc)
        {
            Debug.WriteLine(exc.Message);
        }
}
午後ずっとこのエラーが発生しています。receive メソッドが呼び出されると、接続作成の非同期性が終了する必要があります。