title: Error The client and the server cannot communicate, since they do not have a common algorithm
body: <p>I upgraded to a Windows 10 PRO 20H2 computer which has a .net desktop application with wpf. (.net version 4.8) When trying to communicate with a service that only supports SSL3 I get an error. By code I do it as follows</p>
  <pre><code>/*El ws no soporta tls sino ssl*/
  ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
  
  /*Como no hay certificado instalado confiar todos*/
  ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
  </code></pre>
  <p>Error that appears in the application log.</p>
  <pre><code>System.Net.Http.HttpRequestException: Error al enviar la solicitud. ---&gt; System.Net.WebException: Se ha terminado la conexión: Error inesperado de recepción. ---&gt; System.ComponentModel.Win32Exception: El cliente y el servidor no pueden comunicarse, ya que no poseen un algoritmo común
     en System.Net.SSPIWrapper.AcquireCredentialsHandle(SSPIInterface SecModule, String package, CredentialUse intent, SecureCredential scc)
     en System.Net.Security.SecureChannel.AcquireCredentialsHandle(CredentialUse credUsage, SecureCredential&amp; secureCredential)
     en System.Net.Security.SecureChannel.AcquireClientCredentials(Byte[]&amp; thumbPrint)
     en System.Net.Security.SecureChannel.GenerateToken(Byte[] input, Int32 offset, Int32 count, Byte[]&amp; output)
     en System.Net.Security.SecureChannel.NextMessage(Byte[] incoming, Int32 offset, Int32 count)
     en System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
     en System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest)
     en System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
     en System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
     en System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
     en System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
     en System.Net.TlsStream.ProcessAuthentication(LazyAsyncResult result)
     en System.Net.TlsStream.BeginWrite(Byte[] buffer, Int32 offset, Int32 size, AsyncCallback asyncCallback, Object asyncState)
     en System.Net.ConnectStream.WriteHeaders(Boolean async)
     --- Fin del seguimiento de la pila de la excepción interna ---
     en System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult, TransportContext&amp; context)
     en System.Net.Http.HttpClientHandler.GetRequestStreamCallback(IAsyncResult ar)
     --- Fin del seguimiento de la pila de la excepción interna ---
     en System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
     en System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
     en System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
     en Kiosco.Helpers.LoggedClient.&lt;Post&gt;d__3.MoveNext() |    en System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
     en System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
     en System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
     en Kiosco.Helpers.LoggedClient.&lt;Post&gt;d__3.MoveNext()
  </code></pre>
  <p>System events failed
  <img src="https://i.stack.imgur.com/4aNan.png" alt="enter image description here" /></p>