I am getting this error in my python code. "OSError: [WinError 10038] An operation was attempted on something that is not a socket"

In my python project I have a working server. Now I am making the client side, but I keep getting the "OSError: [WinError 10038] An operation was attempted on something that is not a socket" error. I looked for solutions but most of them involved the persons code being inside of a while loop and they forgot to close the connection or something like that. My code is not like that and I have failed to find a solution. So if anyone knows the answer and the explanation to the answer please help. By the way I am following a tutorial for this.

I am getting the error on the send_message() function on line 18.

Here is my code (I have a working .kv file but if that is needed I can post it too):

import kivy
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout

import socket
import threading

kivy.require("1.9.0")

client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

class MyRoot(BoxLayout):

    def __init__(self):
        super(MyRoot, self).__init__()

    def send_message(self):
        client.send(f"{self.nickname_text.text}: {self.message_text.text}".encode("utf-8"))

    def connect_to_server(self):
        if self.nickname_text != "":
            client.connect((self.ip_text.text, 9999))
            message = client.recv(1024).decode("utf-8")
            if message == "NICK":
                client.send(self.nickname_text.text.encode("utf-8"))
                self.send_btn.disabled = False
                self.message_text.disabled = False
                self.connect_btn.disabled = True
                self.ip_text.disabled = True

                self.make_invisible(self.connection_grid)
                self.make_invisible(self.connect_btn)

                thread = threading.Thread(target=self.receive)
                thread.start()

    def make_invisible(self, widget):
        widget.visible = False
        widget.size_hint_x = None
        widget.size_hint_y = None
        widget.height = 0
        widget.width = 0
        widget.text = ""
        widget.opacity = 0

    def receive(self):
        stop = False
        while not stop:
            try:
                message = client.recv(1024).decode("utf-8")
                self.chat_text.text += message + "n"
            except:
                print("ERROR")
                client.close()
                stop = True




class WebChat(App):

    def build(self):
        return MyRoot()

webChat = WebChat()
webChat.run()