Error "AttributeError: 'NoneType' object has no attribute 'send'"

[Avarong]

When trying to use websockets.py for subscribing to idex data, ia have an error: " Traceback (most recent call last): File "C:/Users/Administrator/PycharmProjects/untitled/IDEXbot.py", line 141, in loop.run_until_complete(main()) File "C:\Users\Administrator\miniconda3\lib\asyncio\base_events.py", line 583, in run_until_complete return future.result() File "C:/Users/Administrator/PycharmProjects/untitled/IDEXbot.py", line 97, in main await ism.subscribe(SubscribeCategory.markets,subscribe_list,['market_cancels', 'market_orders', 'market_trades']) File "C:\Users\Administrator\PycharmProjects\untitled\idex\asyncio\websockets.py", line 246, in subscribe await self._conn.send_message(category, req_msg) File "C:\Users\Administrator\PycharmProjects\untitled\idex\asyncio\websockets.py", line 144, in send_message await self._socket.send(socket_msg) AttributeError: 'NoneType' object has no attribute 'send' Unclosed client session client_session: <aiohttp.client.ClientSession object at 0x000000E14FE061C8> Unclosed connector connections: ['[(<aiohttp.client_proto.ResponseHandler object at 0x000000E14FDF4358>, 355.937)]'] connector: <aiohttp.connector.TCPConnector object at 0x000000E14FE06208> " How should i fix that?