TypeError("'Process' object is not callable",) in once method

[patrick wong]

Hi all,

I attempt to upgrade the CherryPy and ws4py in my project server.  I use CherryPy (17.4.2) and ws4py (0.5.1).  However, the server will terminate the established websocket whenever data are received from client:

[2021-12-17 16:33:13,741] ERROR Terminating websocket [Local => 192.168.x.x:443 | Remote => 118.140.205.42:65248] due to exception: TypeError("'Process' object is not callable",) in once method

The once method in websocket.py throws the exception when it attempts to call process (line 410) :

            if not self.process(self.buf[:requested]):
                return False
            self.buf = self.buf[requested:]

The websocket can be maintained if the client does not send any data.

Could anybody kindly advise what would cause the problem?

Thanks in advance.

Regards,

Patrick Wong