"The client is using an unsupported version of the Socket.IO or Engine.IO protocols"

I use python flask as server frame React as front use socket.io-client 3.0.4 as client python-socketio 5.0.0 as server but l can not connect always “The client is using an unsupported version of the Socket.IO or Engine.IO protocols”

    const socket = io("ws://127.0.0.1:8888");
    // client-side
    socket.on("connect", () => {
      console.log(socket.id); // x8WIv7-mJelg7on_ALbx
    });

from flask import Flask,abort,jsonify,request
from dataProcess import handleDataProcess
import socketio
import setting 

app = Flask(__name__)
app.config['SECRET_KEY'] = 'secret!'
app.config.from_object(setting.DevConfig)
sio = socketio.Server()
print({sio})
app.wsgi_app = socketio.WSGIApp(sio, app.wsgi_app)


@app.route('/api/dataprocess',methods=['POST'])
def dataProcess():
    params = request.json.get('params')
    result = handleDataProcess(params)
    emit.SocketIO('dataprocesssuccess',{'test':11})
    return jsonify(result)
@sio.event
def connect():
    print("I'm connected!")

@sio.event
def connect_error():
    print("The connection failed!")

@sio.event
def disconnect():
    print("I'm disconnected!")
@sio.on('my_event')
def my_event(data):
    print('Received data: ', data)
if __name__ == '__main__' :  
    app.run(host='127.0.0.1',port = 8888)

i want to konw why who can help me # #

[zkquin]

I think I’ve found a solution as I’ve just had to deal with this issue. I believe it’s due to our lovely miguelgrinberg also updating the python-engineio just make sure you pull 3.13.2 if your using say 4.6.1. Otherwise 4.0.0 python-engineio will be pulled which is causing incompatibility issues.

[kalaersun]

It’s exactly what the error says. The version of the Socket.IO client that you are using is incompatible with the version of the server. Either upgrade your client, or downgrade your server. The README of this repo has a table that shows you which JS and Python versions are compatible.

socket.io-client 3.0.4 as client python-socketio 5.0.0 as server i use this two i don not konw where is the porblem