selenium webdriver error A exception with a null response was thrown sending an HTTP request to the remote WebDriver server for URL

I am using selenium webdriver 3.12.0.0, with chromedriver 85.0.4183.38, and chrome 86.0.4240.111. My system was working ok until 3 days ago, when suddenly when I open several chromedriver instances.
I get an error saying:

An exception with a null response was thrown sending an HTTP request to the remote WebDriver server for URL http://localhost:59457/session/fd655995397405a92e5dba53f86ce963/window. The status of the exception was ConnectFailure, and the message was:

Unable to connect to the remote server Stack trace: at OpenQA.Selenium.Remote.HttpCommandExecutor.MakeHttpRequest(HttpRequestInfo requestInfo) at OpenQA.Selenium.Remote.

Or:

WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it 127.0.0.1:59008 at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress) at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception) --- End of inner exception stack trace --- at System.Net.HttpWebRequest.GetRequestStream(TransportContext& context) at

I read about it and I tried to upgrade chromedriver and webdriver I tried:

1. chromedriver 85.0.4183.87 with webdriver 3.141.59 and webdriver v4.0.30319
2. chromedriver 86.0.4240.22 with webdriver 3.141.59 and webdriver v4.0.30319

This did not work. What else can I do?