Decoded string is not a valid IDN name

Hmm, can’t seem to figure this one out 😕.

Platform: Linux x64

YoutubeClient _youtubeClient = new YoutubeClient();
var mediaInfoSet = await _youtubeClient.GetVideoMediaStreamInfosAsync(videoId);

System.Net.Http.HttpRequestException: The SSL connection could not be established, see inner exception. ---> System.Security.Authentication.AuthenticationException: Authentication failed, see inner exception. ---> System.ArgumentException: Decoded string is not a valid IDN name.
Parameter name: unicode
   at System.Globalization.IdnMapping.GetAsciiCore(Char* unicode, Int32 count)
   at System.Globalization.IdnMapping.GetAscii(String unicode, Int32 index, Int32 count)
   at Interop.OpenSsl.AllocateSslContext(SslProtocols protocols, SafeX509Handle certHandle, SafeEvpPKeyHandle certKeyHandle, EncryptionPolicy policy, SslAuthenticationOptions sslAuthenticationOptions)
   at System.Net.Security.SafeDeleteSslContext..ctor(SafeFreeSslCredentials credential, SslAuthenticationOptions sslAuthenticationOptions)
   at System.Net.Security.SslStreamPal.HandshakeInternal(SafeFreeCredentials credential, SafeDeleteContext& context, SecurityBuffer inputBuffer, SecurityBuffer outputBuffer, SslAuthenticationOptions sslAuthenticationOptions)
   --- End of inner exception stack trace ---
   at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message, AsyncProtocolRequest asyncRequest, ExceptionDispatchInfo exception)
   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
   at System.Net.Security.SslStream.BeginAuthenticateAsClient(SslClientAuthenticationOptions sslClientAuthenticationOptions, CancellationToken cancellationToken, AsyncCallback asyncCallback, Object asyncState)
   at System.Net.Security.SslStream.<>c.<AuthenticateAsClientAsync>b__47_0(SslClientAuthenticationOptions arg1, CancellationToken arg2, AsyncCallback callback, Object state)
   at System.Threading.Tasks.TaskFactory`1.FromAsyncImpl[TArg1,TArg2](Func`5 beginMethod, Func`2 endFunction, Action`1 endAction, TArg1 arg1, TArg2 arg2, Object state, TaskCreationOptions creationOptions)
   at System.Threading.Tasks.TaskFactory.FromAsync[TArg1,TArg2](Func`5 beginMethod, Action`1 endMethod, TArg1 arg1, TArg2 arg2, Object state, TaskCreationOptions creationOptions)
   at System.Threading.Tasks.TaskFactory.FromAsync[TArg1,TArg2](Func`5 beginMethod, Action`1 endMethod, TArg1 arg1, TArg2 arg2, Object state)
   at System.Net.Security.SslStream.AuthenticateAsClientAsync(SslClientAuthenticationOptions sslClientAuthenticationOptions, CancellationToken cancellationToken)
   at System.Net.Http.ConnectHelper.EstablishSslConnectionAsyncCore(Stream stream, SslClientAuthenticationOptions sslOptions, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at System.Net.Http.ConnectHelper.EstablishSslConnectionAsyncCore(Stream stream, SslClientAuthenticationOptions sslOptions, CancellationToken cancellationToken)
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at System.Net.Http.HttpConnectionPool.CreateConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at System.Net.Http.HttpConnectionPool.WaitForCreatedConnectionAsync(ValueTask`1 creationTask)
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.DecompressionHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.HttpClient.FinishSendAsyncUnbuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)
   at YoutubeExplode.Internal.HttpClientEx.HeadAsync(HttpClient client, String requestUri)
   at YoutubeExplode.YoutubeClient.GetVideoMediaStreamInfosAsync(String videoId)

[Adilkp796]

Add the following at the beginning of your code in main method Program.cs AppContext.SetSwitch("System.Net.Http.UseSocketsHttpHandler", false);

[TheTrigger]

Here the fix: https://stackoverflow.com/a/53598509 AppContext.SetSwitch("System.Net.Http.UseSocketsHttpHandler", false);