builtins.AttributeError: 'Stream' object has no attribute 'len'

[byehack]

on py36 win10:

[*] INFO:       keyboard layout set to en
Unhandled Error
Traceback (most recent call last):
  File "D:\python\lib\site-packages\twisted\python\log.py", line 103, in callWithLogger
    return callWithContext({"system": lp}, func, *args, **kw)
  File "D:\python\lib\site-packages\twisted\python\log.py", line 86, in callWithContext
    return context.call({ILogContext: newCtx}, func, *args, **kw)
  File "D:\python\lib\site-packages\twisted\python\context.py", line 122, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "D:\python\lib\site-packages\twisted\python\context.py", line 85, in callWithContext
    return func(*args,**kw)
--- <exception caught here> ---
  File "D:\python\lib\site-packages\qtreactor\qt4base.py", line 100, in _read
    data = w.doRead()
  File "D:\python\lib\site-packages\twisted\internet\tcp.py", line 243, in doRead
    return self._dataReceived(data)
  File "D:\python\lib\site-packages\twisted\internet\tcp.py", line 249, in _dataReceived
    rval = self.protocol.dataReceived(data)
  File "c:\users\mohammad      t\downloads\rdpy-python3\rdpy\protocol\rdp\nla\cssp.py", line 208, in dataReceived
    self._layer.dataReceived(data)
  File "c:\users\mohammad      t\downloads\rdpy-python3\rdpy\core\layer.py", line 209, in dataReceived
    self.recv(expectedData)
  File "c:\users\mohammad      t\downloads\rdpy-python3\rdpy\protocol\rdp\tpkt.py", line 141, in readHeader
    data.readType(version)
  File "c:\users\mohammad      t\downloads\rdpy-python3\rdpy\core\type.py", line 894, in readType
    if self.dataLen() == 0 and value._optional:
  File "c:\users\mohammad      t\downloads\rdpy-python3\rdpy\core\type.py", line 863, in dataLen
    return self.len - self.pos
builtins.AttributeError: 'Stream' object has no attribute 'len'

[*] INFO:       Lost connection : [Failure instance: Traceback: <class 'AttributeError'>: 'Stream' object has no attribute 'len'
D:\python\lib\site-packages\twisted\python\log.py:86:callWithContext
D:\python\lib\site-packages\twisted\python\context.py:122:callWithContext
D:\python\lib\site-packages\twisted\python\context.py:85:callWithContext
D:\python\lib\site-packages\qtreactor\qt4base.py:107:_read
--- <exception caught here> ---
D:\python\lib\site-packages\qtreactor\qt4base.py:100:_read
D:\python\lib\site-packages\twisted\internet\tcp.py:243:doRead
D:\python\lib\site-packages\twisted\internet\tcp.py:249:_dataReceived
c:\users\mohammad      t\downloads\rdpy-python3\rdpy\protocol\rdp\nla\cssp.py:208:dataReceived
c:\users\mohammad      t\downloads\rdpy-python3\rdpy\core\layer.py:209:dataReceived
c:\users\mohammad      t\downloads\rdpy-python3\rdpy\protocol\rdp\tpkt.py:141:readHeader
c:\users\mohammad      t\downloads\rdpy-python3\rdpy\core\type.py:894:readType
c:\users\mohammad      t\downloads\rdpy-python3\rdpy\core\type.py:863:dataLen
]```