Describe the bug

Message is Incomplete error in OpenMu app
In signalr.js file we get this error:

signalr.js:2857 Uncaught Error: Message is incomplete

at Function.TextMessageFormat.parse (signalr.js:2857)
at JsonHubProtocol.parseMessages (signalr.js:4852)
at HubConnection.processIncomingData (signalr.js:2357)
at WebSocketTransport.HubConnection.connection.onreceive (signalr.js:1923)
at WebSocket.webSocket.onmessage (signalr.js:4740)

Message on .NET 5 Prev5 :
{"type":1,"target":"Initialize","arguments":[[{"maps":[],"id":0,"description":"Server 0","state":0,"onlinePlayerCount":0,"maximumPlayers":1000,"type":1},{"maps":[],"id":1,"description":"Server 1","state":0,"onlinePlayerCount":0,"maximumPlayers":1000,"type":1},{"maps":[],"id":2,"description":"Server 2","state":0,"onlinePlayerCount":0,"maximumPlayers":1000,"type":1}]

Message on .NET 5 Prev4 :
{"type":1,"target":"Initialize","arguments":[[{"maps":[],"id":0,"description":"Server 0","state":0,"onlinePlayerCount":0,"maximumPlayers":1000,"type":1}],[{"settings":{"id":"abe33204-0ca9-4357-bb01-825aa1e96fab","client":{"id":"0b342393-7dc5-4d03-8999-a9dbfd0cb987","season":6,"episode":3,"language":1,"version":"MTA0MDQ=","serial":"azFQazJqY0VUNDhteEwzYg==","description":"Season 6 Episode 3 GMO Client"},"serverId":0,"description":"Connect Server (Season 6 Episode 3 English)","disconnectOnUnknownPacket":true,"maximumReceiveSize":6,"clientListenerPort":44405,"timeout":"00:01:00","currentPatchVersion":"AQMr","patchAddress":"patch.muonline.webzen.com","maxConnectionsPerAddress":30,"checkMaxConnectionsPerAddress":true,"maxConnections":10000,"listenerBacklog":100,"maxFtpRequests":1,"maxIpRequests":5,"maxServerListRequests":20},"id":65536,"description":"Connect Server (Season 6 Episode 3 English)","state":0,"onlinePlayerCount":0,"maximumPlayers":10000,"type":2}],[],[]]}

To Reproduce

On the repo machine (https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workitems/edit/1129671)

1. On CMD, navigate to C:\Users\appcompat\Documents\OpenMU
2. Run : dotnet MUnique.OpenMU.Startup.dll
3. Wait for admin panel to initialize
   4)In Browser, Open http://localhost:1234/admin
   Since "C:\Users\appcompat\Documents\OpenMU\MUnique.OpenMU.Startup.runtimeconfig.json" set to 5.0.0-preview.5.20269.6, app will use .NET5 runtime. This is issue is not repro on .NET Core 3

Further technical details

• ASP.NET Core version
  Microsoft.NETCore.App 5.0.0-preview.5.20268.9
• Include the output of dotnet --info
  .NET SDK (reflecting any global.json):
  Version: 5.0.100-preview.5.20270.37
  Commit: b262a37641

Runtime Environment:
OS Name: Windows
OS Version: 10.0.18363
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\5.0.100-preview.5.20270.37\

Host (useful for support):
Version: 5.0.0-preview.5.20268.9
Commit: f3c276fe20

.NET SDKs installed:
3.1.300 [C:\Program Files\dotnet\sdk]
5.0.100-preview.5.20270.37 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.1.18 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.18 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.4 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.0-preview.5.20269.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.18 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.0-preview.5.20268.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.0-preview.5.20269.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

• The IDE (VS / VS Code/ VS4Mac) you're running on, and it's version
  VS2019

Verify Scenarios:
1). Windows 10 RS5 X64 + .NET Core SDK build 5.0.100-preview.5.20270.37: Fail
2). Windows 10 RS5 X64 + .NET Core SDK build 5.0.100-preview.4.20258.7: Pass
3). Windows 10 RS5 X64 + .NET Core SDK build 3.1.300:Pass

Expected Result:

Actual Result:

cc @dotnet-actwx-bot