Why did python raise an AssertionError on some unsuccessful assumptions in the ZeroMQ client?

Question

My server _{(not published here, written in java) is} set to run only after the event is triggered, and the client _{(written in python) is} constantly running in the background, waiting for the server. ZeroMQ ZeroMQ

For a considerable period of time, the python client continues to work properly, and then crashes with this error:

Assertion failed: Connection reset by peer (bundled\zeromq\src\signaler.cpp:298)

This occurs when the server does not start at a long interval.

The client application (python) is in the following form

import zmq

context = zmq.Context()
socket  = context.socket( zmq.REQ )

socket.connect( "tcp://localhost:5555" )

socket.send( b"ReadySIG_From_Python_Emitted" )
message = socket.recv()
print( "OrderDetails %s" % ( message ) )

socket.send( b"TERMINATE" )
exit()