System.IO.InvalidDataException: Missing required property 'protocol' and System.IO.InvalidDataException: Missing required property 'type' when using Java client

[wanlwanl]

Describe the bug

A clear and concise description of what the bug is.
When I use Java client, it's easy to get 2 kinds of error on server:
Missing required property 'protocol'. and System.IO.InvalidDataException: Missing required property 'type'.

To Reproduce

Use this code to start/stop clients:

import com.microsoft.signalr.HubConnection;
import com.microsoft.signalr.HubConnectionBuilder;
import io.reactivex.Single;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class Chat {
    public static HubConnection create(boolean service)
    {
        if (service) {
            HubConnection hubConnection = HubConnectionBuilder
//                .create("http://localhost:5000/chat")
                    .create("http://localhost:8080/client/?hub=hub")
                    .withAccessTokenProvider(Single.defer(() -> {

                        return Single.just("...");
                    }))
                    .build();

            return hubConnection;
        } else {
            HubConnection hubConnection = HubConnectionBuilder
                .create("http://localhost:5000/chat")
                    .build();

            return hubConnection;
        }


    }

    public static void main(String[] args) throws Exception {
        ThreadPoolExecutor executor = new ThreadPoolExecutor(100, 200, 300,
                TimeUnit.MILLISECONDS, new ArrayBlockingQueue<Runnable>(3),
                new ThreadPoolExecutor.CallerRunsPolicy());

        HubConnection hubConnection = create(false);

        for(int i=0;i<10;i++) start(executor, hubConnection);
        for(int i=0;i<10;i++) stop(executor, hubConnection);

    }

    public static void stop(ThreadPoolExecutor executor, HubConnection hubConnection) {
        executor.execute(() -> {
            while (true) {
                try {
                    hubConnection.stop();
                    Thread.sleep((int) (Math.random() * 500));
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public static void start(ThreadPoolExecutor executor, HubConnection hubConnection) {
        executor.execute(() -> {
            while (true) {
                try {
                    hubConnection.start();
                    Thread.sleep((int) (Math.random() * 50));
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

Exceptions (if any)

System.IO.InvalidDataException: Missing required property 'protocol'. Message content: {"type":6}
   at Microsoft.AspNetCore.SignalR.Protocol.HandshakeProtocol.TryParseRequestMessage(ReadOnlySequence`1& buffer, HandshakeRequestMessage& requestMessage)
   at Microsoft.AspNetCore.SignalR.HubConnectionContext.HandshakeAsync(TimeSpan timeout, IReadOnlyList`1 supportedProtocols, IHubProtocolResolver protocolResolver, IUserIdProvider userIdProvider, Boolean enableDetailedErrors)

and

System.IO.InvalidDataException: Missing required property 'type'.
   at Microsoft.AspNetCore.SignalR.Protocol.JsonHubProtocol.ParseMessage(Utf8BufferTextReader textReader, IInvocationBinder binder)
   at Microsoft.AspNetCore.SignalR.Protocol.JsonHubProtocol.TryParseMessage(ReadOnlySequence`1& input, IInvocationBinder binder, HubMessage& message)
   at Microsoft.AspNetCore.SignalR.HubConnectionHandler`1.DispatchMessagesAsync(HubConnectionContext connection)
   at Microsoft.AspNetCore.SignalR.HubConnectionHandler`1.RunHubAsync(HubConnectionContext connection)

Further technical details

• ASP.NET Core version
• Include the output of dotnet --info
• The IDE (VS / VS Code/ VS4Mac) you're running on, and it's version

Signalr java client:

<dependency>
            <groupId>com.microsoft.signalr</groupId>
            <artifactId>signalr</artifactId>
            <version>5.0.0-preview.3.20215.14</version>
        </dependency>

.NET SDK (reflecting any global.json):
 Version:   5.0.100-preview.5.20279.10
 Commit:    8139f1b74e

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.17763
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\5.0.100-preview.5.20279.10\

Host (useful for support):
  Version: 5.0.0-preview.5.20278.1
  Commit:  4ae4e2fe08

.NET SDKs installed:
  2.1.700 [C:\Program Files\dotnet\sdk]
  2.2.207 [C:\Program Files\dotnet\sdk]
  3.1.200 [C:\Program Files\dotnet\sdk]
  5.0.100-preview.5.20279.10 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.All 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.16 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.16 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.0-preview.5.20279.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.16 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.0-preview.5.20278.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.0-preview.5.20278.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
  https://aka.ms/dotnet-download

IDE:
IntelliJ IDEA 2020.1.2 (Community Edition)
Build #IC-201.7846.76, built on June 1, 2020
Runtime version: 11.0.7+10-b765.53 amd64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
Windows 10 10.0
GC: ParNew, ConcurrentMarkSweep
Memory: 2014M
Cores: 4

[BrennanConroy]

Should be fixed with #24166