WebClient SSL Error: "System.Net.WebException: The SLL connection could not be established" – Telegram API

Hi, dear stranger!

I made a console application for my telegram bot. On my laptop it works perfectly, but on my PC which i want to use as a server this code gets an error. I spent the whole day trying to fix it and went through a lot of similar topics over here but didn’t find any solution.

The trouble appears at this part of code:

try {
    var webClient = new WebClient();
    webClient.DownloadString($"{startUrl}/sendMessage?chat_id={messageFromId}&text=" + number.ToString());
}

 catch (Exception e){
    Console.WriteLine(e.ToString());
}

How can i avoid SSL certificate since i am not looking for a real security here?

The error is below:

> System.Net.WebException: The SSL connection could not be established,
> see inner exception. Unable to read data from the transport
> connection: Удаленный хост принудительно разорвал существующее
> подключение..  ---> System.Net.Http.HttpRequestException: The SSL
> connection could not be established, see inner exception.  --->
> System.IO.IOException: Unable to read data from the transport
> connection: Удаленный хост принудительно разорвал существующее
> подключение..  ---> System.Net.Sockets.SocketException (10054):
> Удаленный хост принудительно разорвал существующее подключение.    ---
> End of inner exception stack trace ---    at
> System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError
> error, CancellationToken cancellationToken)    at
> System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.GetResult(Int16
> token)    at System.Net.FixedSizeReader.ReadPacketAsync(Stream
> transport, AsyncProtocolRequest request)    at
> System.Net.Security.SslStream.ThrowIfExceptional()    at
> System.Net.Security.SslStream.InternalEndProcessAuthentication(LazyAsyncResult
> lazyResult)    at
> System.Net.Security.SslStream.EndProcessAuthentication(IAsyncResult
> result)    at
> System.Net.Security.SslStream.EndAuthenticateAsClient(IAsyncResult
> asyncResult)    at
> System.Net.Security.SslStream.<>c.<AuthenticateAsClientAsync>b__65_1(IAsyncResult
> iar)    at
> System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult
> iar, Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean
> requiresSynchronization)
> --- End of stack trace from previous location where exception was thrown ---

What i’ve already tried:

1) Puting this before the WebClient request. Doesn’t help:

ServicePointManager.ServerCertificateValidationCallback +=
   delegate (object sender, X509Certificate certificate, X509Chain chain,
          SslPolicyErrors sslPolicyErrors)
   {
       return true;
   };

2) Using delegates to disable SSL

ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };

3) Your idea is next?

Or may be i just was using wrongly the previous solutions?
Don’t pass by, let’s try your ideas!

Thanks!