invalid data or unsupported protocol version

[zhangjiechina001]

import OpenOPC
opc=OpenOPC.open_client(host='127.0.0.1',port=7766)
print(opc.servers())

F:\Anaconda\envs\PyQt5\python.exe C:/Users/Administrator/PycharmProjects/-/opc/sample01.py
Traceback (most recent call last):
File "C:/Users/Administrator/PycharmProjects/-/opc/sample01.py", line 2, in
opc=OpenOPC.open_client(host='127.0.0.1',port=7766)
File "F:\Anaconda\envs\PyQt5\lib\site-packages\OpenOPC.py", line 131, in open_client
return server_obj.create_client()
File "F:\Anaconda\envs\PyQt5\lib\site-packages\Pyro4\core.py", line 275, in getattr
self._pyroGetMetadata()
File "F:\Anaconda\envs\PyQt5\lib\site-packages\Pyro4\core.py", line 615, in _pyroGetMetadata
self.__pyroCreateConnection()
File "F:\Anaconda\envs\PyQt5\lib\site-packages\Pyro4\core.py", line 596, in __pyroCreateConnection
connect_and_handshake(conn)
File "F:\Anaconda\envs\PyQt5\lib\site-packages\Pyro4\core.py", line 535, in connect_and_handshake
msg = message.Message.recv(conn, [message.MSG_CONNECTOK, message.MSG_CONNECTFAIL], hmac_key=self._pyroHmacKey)
File "F:\Anaconda\envs\PyQt5\lib\site-packages\Pyro4\message.py", line 168, in recv
msg = cls.from_header(connection.recv(cls.header_size))
File "F:\Anaconda\envs\PyQt5\lib\site-packages\Pyro4\message.py", line 152, in from_header
raise errors.ProtocolError("invalid data or unsupported protocol version")
Pyro4.errors.ProtocolError: invalid data or unsupported protocol version