What does this error mean in Redis?

Question

Redis

There is a simple hello world for radishes:

ConfigurationOptions co = new ConfigurationOptions();
      co.EndPoints.Add("127.0.0.1:6379");
      
      ConnectionMultiplexer redis = ConnectionMultiplexer.Connect(co);
      IDatabase db = redis.GetDatabase();
      string value = "abcdefg";
      db.StringSet("mykey", value);

       value = db.StringGet("mykey");
      Console.WriteLine(value); // writes: "abcdefg"

but when 3 redis is running, an error occurs:

System.AggregateException: Произошла одна или несколько ошибок. ---> System.Security.VerificationException: Метод System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1
[System.Boolean].AwaitUnsafeOnCompleted: аргумент типа "Microsoft.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter
[StackExchange.Redis.ServerEndPoint]" не удовлетворяет ограничению на параметр типа "TAwaiter".

   в StackExchange.Redis.ConnectionMultiplexer.<ReconfigureAsync>d__2d.MoveNext()
   в System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.Start[TStateMachine](TStateMachine& stateMachine)
   в StackExchange.Redis.ConnectionMultiplexer.ReconfigureAsync(Boolean first, Boolean reconfigureAll, TextWriter log, EndPoint blame, String cause, Boolean publishReconfigure, CommandFlags publishReconfigureFlags)
   в StackExchange.Redis.ConnectionMultiplexer.<>c__DisplayClass29.<ConnectImpl>b__26() в c:\TeamCity\buildAgent\work\3ae0647004edff78\StackExchange.Redis\StackExchange\Redis\ConnectionMultiplexer.cs:строка 815
   в System.Threading.Tasks.Task`1.InnerInvoke()
   в System.Threading.Tasks.Task.Execute()
   --- End of inner exception stack trace ---
   в System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   в System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   в System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout)
   в StackExchange.Redis.ConnectionMultiplexer.ConnectImpl(Func`1 multiplexerFactory, TextWriter log) в c:\TeamCity\buildAgent\work\3ae0647004edff78\StackExchange.Redis\StackExchange\Redis\ConnectionMultiplexer.cs:строка 817
   в StackExchange.Redis.ConnectionMultiplexer.Connect(ConfigurationOptions configuration, TextWriter log) в c:\TeamCity\buildAgent\work\3ae0647004edff78\StackExchange.Redis\StackExchange\Redis\ConnectionMultiplexer.cs:строка 803
   в qasd.MainForm..ctor() в c:\Users\OSSDO2\Documents\SharpDevelop Projects\qasd\qasd\MainForm.cs:строка 35
   в qasd.Program.Main(String[] args) в c:\Users\OSSDO2\Documents\SharpDevelop Projects\qasd\qasd\Program.cs:строка 27

I can't figure out what he wants from me :)