NotImplemented exception when doing a challenge for cookies middleware

[Praburaj]

Looks like K10 has a IdnMapping class stub with no implementation.

An unhandled exception occurred while processing the request.

NotImplementedException: The method or operation is not implemented.
Microsoft.AspNet.Abstractions.HostString.IdnMapping.GetAscii(String unicode, Int32 index, Int32 count)

Stack Query Cookies Headers Environment
NotImplementedException: The method or operation is not implemented.
Microsoft.AspNet.Abstractions.HostString.IdnMapping.GetAscii(String unicode, Int32 index, Int32 count)
Microsoft.AspNet.Abstractions.HostString.ToUriComponent()
Microsoft.AspNet.Abstractions.HostString.ToString()
System.String.Concat(Object[] args)
Microsoft.AspNet.Security.Cookies.CookieAuthenticationHandler.ApplyResponseChallenge()
Microsoft.AspNet.Security.Infrastructure.AuthenticationHandler.ApplyResponseCore()
Microsoft.AspNet.Security.Infrastructure.AuthenticationHandler.b__6()
System.Threading.LazyInitializer.EnsureInitializedCore[T](T& target, Boolean& initialized, Object& syncLock, Func1 valueFactory) System.Threading.LazyInitializer.EnsureInitialized[T](T& target, Boolean& initialized, Object& syncLock, Func1 valueFactory)
Microsoft.AspNet.Security.Infrastructure.AuthenticationHandler.ApplyResponse()
Microsoft.AspNet.Security.Infrastructure.AuthenticationHandler.OnSendingHeaderCallback(Object state)
Microsoft.AspNet.Server.WebListener.Response.NotifyOnSendingHeaders()
Microsoft.AspNet.Server.WebListener.Response.ComputeHeaders(Boolean endOfRequest)
Microsoft.AspNet.Server.WebListener.ResponseStream.ComputeLeftToWrite(Boolean endOfRequest)
Microsoft.AspNet.Server.WebListener.ResponseStream.WriteAsync(Byte[] buffer, Int32 offset, Int32 size, CancellationToken cancel)
System.IO.Stream.WriteAsync(Byte[] buffer, Int32 offset, Int32 count)
Microsoft.AspNet.PipelineCore.DefaultHttpResponse.WriteAsync(String data)
Startup.b__0(HttpContext context) in Startup.cs
return context.Response.WriteAsync("Authenticate..");

[Tratcher]

Fixed: aspnet/HttpAbstractions@165effe