Launch address already in use after initial launch of Blazor app

Issue Description

Presented with error: “Address https://127.0.01:5001 address already in use” after initial launch of application. If I end the .Net Core Host process I experience the same issue presented here: #4056

This error doesn’t present itself if application is launched in Visual Studio as opposed to VSCode.

Steps to Reproduce

1. Launch Blazor WebAssembly app
2. Stop application
3. Launch application again

Expected Behavior

Application launches without error to home page

Actual Behavior

Error message received: “The terminal process “cmd.exe ‘/c’, ‘chcp 65001 >NUL & dotnet run’” terminated with exit code: 3762504530”

Exception Log

Application: dotnet.exe CoreCLR Version: 4.700.20.47201 .NET Core Version: 3.1.9 Description: The process was terminated due to an unhandled exception. Exception Info: System.IO.IOException: Failed to bind to address https://127.0.0.1:5001: address already in use. ---> Microsoft.AspNetCore.Connections.AddressInUseException: Only one usage of each socket address (protocol/network address/port) is normally permitted. ---> System.Net.Sockets.SocketException (10048): Only one usage of each socket address (protocol/network address/port) is normally permitted. at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, String callerName) at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress) at System.Net.Sockets.Socket.Bind(EndPoint localEP) at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind() --- End of inner exception stack trace --- at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind() at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportFactory.BindAsync(EndPoint endpoint, CancellationToken cancellationToken) at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.<>c__DisplayClass21_0`1.<<StartAsync>g__OnBind|0>d.MoveNext() --- End of stack trace from previous location where exception was thrown --- at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context) --- End of inner exception stack trace --- at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.LocalhostListenOptions.BindAsync(AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.BindAsync(AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IServerAddressesFeature addresses, KestrelServerOptions serverOptions, ILogger logger, Func`2 createBinding) at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken) at Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync(CancellationToken cancellationToken) at Microsoft.Extensions.Hosting.Internal.Host.StartAsync(CancellationToken cancellationToken) at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token) at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token) at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.Run(IHost host) at Microsoft.AspNetCore.Components.Web.DevServer.Commands.ServeCommand.Execute() at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args) at Microsoft.AspNetCore.Components.WebAssembly.DevServer.Program.Main(String[] args)

OmniSharp log

Starting OmniSharp server at 10/28/2020, 5:21:19 PM Target: c:\dev\BlazorTestProj

OmniSharp server started. Path: c:\Users\username.vscode\extensions\ms-dotnettools.csharp-1.23.4.omnisharp\1.37.3\OmniSharp.exe PID: 7304

    Starting OmniSharp on Windows 6.2.9200.0 (x64)

    DotNetPath set to dotnet

    Located 2 MSBuild instance(s)
        1: Visual Studio Professional 2017 15.9.28307.1000 - "C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\15.0\Bin"
        2: StandAlone 16.8.0 - "c:\Users\username\.vscode\extensions\ms-dotnettools.csharp-1.23.4\.omnisharp\1.37.3\.msbuild\Current\Bin"

    It looks like you have Visual Studio lower than VS 2019 16.3 installed.

Try updating Visual Studio to the most recent release to enable better MSBuild support. info: OmniSharp.MSBuild.Discovery.MSBuildLocator MSBUILD_EXE_PATH environment variable set to ‘c:\Users\username.vscode\extensions\ms-dotnettools.csharp-1.23.4.omnisharp\1.37.3.msbuild\Current\Bin\MSBuild.exe’ info: OmniSharp.MSBuild.Discovery.MSBuildLocator Registered MSBuild instance: StandAlone 16.8.0 - “c:\Users\username.vscode\extensions\ms-dotnettools.csharp-1.23.4.omnisharp\1.37.3.msbuild\Current\Bin” CscToolExe = csc.exe CscToolPath = c:\Users\username.vscode\extensions\ms-dotnettools.csharp-1.23.4.omnisharp\1.37.3.msbuild\Current\Bin\Roslyn MSBuildExtensionsPath = c:\Users\username.vscode\extensions\ms-dotnettools.csharp-1.23.4.omnisharp\1.37.3.msbuild MSBuildToolsPath = c:\Users\username.vscode\extensions\ms-dotnettools.csharp-1.23.4.omnisharp\1.37.3.msbuild\Current\Bin info: OmniSharp.Cake.CakeProjectSystem Detecting Cake files in ‘c:\dev\BlazorTestProj’. info: OmniSharp.Cake.CakeProjectSystem Could not find any Cake files info: OmniSharp.MSBuild.ProjectSystem No solution files found in ‘c:\dev\BlazorTestProj’ info: OmniSharp.MSBuild.ProjectManager Queue project update for ‘c:\dev\BlazorTestProj\BlazorTestProj.csproj’ info: OmniSharp.Script.ScriptProjectSystem Detecting CSX files in ‘c:\dev\BlazorTestProj’. info: OmniSharp.Script.ScriptProjectSystem Could not find any CSX files info: OmniSharp.WorkspaceInitializer Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0 info: OmniSharp.MSBuild.ProjectManager Loading project: c:\dev\BlazorTestProj\BlazorTestProj.csproj info: OmniSharp.WorkspaceInitializer Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.Completion.CompletionOptionsProvider, Order: 0 info: OmniSharp.WorkspaceInitializer Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.RenameWorkspaceOptionsProvider, Order: 100 info: OmniSharp.WorkspaceInitializer Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.ImplementTypeWorkspaceOptionsProvider, Order: 110 info: OmniSharp.WorkspaceInitializer Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.BlockStructureWorkspaceOptionsProvider, Order: 140 info: OmniSharp.WorkspaceInitializer Configuration finished. info: OmniSharp.Stdio.Host Omnisharp server running using Stdio at location ‘c:\dev\BlazorTestProj’ on host 15576. info: OmniSharp.MSBuild.ProjectManager Successfully loaded project file ‘c:\dev\BlazorTestProj\BlazorTestProj.csproj’. info: OmniSharp.MSBuild.ProjectManager Adding project ‘c:\dev\BlazorTestProj\BlazorTestProj.csproj’ info: OmniSharp.MSBuild.ProjectManager Update project: BlazorTestProj info: OmniSharp.OmniSharpWorkspace Miscellaneous file: c:\dev\BlazorTestProj\obj\Debug\netstandard2.1\Razor\App.razor.g.cs added to workspace info: OmniSharp.OmniSharpWorkspace Miscellaneous file: c:\dev\BlazorTestProj\obj\Debug\netstandard2.1\Razor\Pages\Index.razor.g.cs added to workspace info: OmniSharp.OmniSharpWorkspace Miscellaneous file: c:\dev\BlazorTestProj\obj\Debug\netstandard2.1\Razor\Pages\FetchData.razor.g.cs added to workspace info: OmniSharp.OmniSharpWorkspace Miscellaneous file: c:\dev\BlazorTestProj\obj\Debug\netstandard2.1\Razor\Pages\Counter.razor.g.cs added to workspace info: OmniSharp.OmniSharpWorkspace Miscellaneous file: c:\dev\BlazorTestProj\obj\Debug\netstandard2.1\Razor\Shared\NavMenu.razor.g.cs added to workspace info: OmniSharp.OmniSharpWorkspace Miscellaneous file: c:\dev\BlazorTestProj\obj\Debug\netstandard2.1\Razor\Shared\SurveyPrompt.razor.g.cs added to workspace info: OmniSharp.OmniSharpWorkspace Miscellaneous file: c:\dev\BlazorTestProj\obj\Debug\netstandard2.1\Razor_Imports.razor.g.cs added to workspace info: OmniSharp.OmniSharpWorkspace Miscellaneous file: c:\dev\BlazorTestProj\obj\Debug\netstandard2.1\Razor\Shared\MainLayout.razor.g.cs added to workspace

C# log

Post the output from Output-->C# here

Environment information

VSCode version: 1.50.1 C# Extension: 1.23.4

Dotnet Information

.NET Core SDK (reflecting any global.json): Version: 3.1.201 Commit: b1768b4ae7

Runtime Environment: OS Name: Windows OS Version: 10.0.18363 OS Platform: Windows RID: win10-x64 Base Path: C:\Program Files\dotnet\sdk\3.1.201\

Host (useful for support): Version: 3.1.9 Commit: 774fc3d6a9

.NET Core SDKs installed: 2.1.508 [C:\Program Files\dotnet\sdk] 2.1.509 [C:\Program Files\dotnet\sdk] 2.1.511 [C:\Program Files\dotnet\sdk] 2.1.701 [C:\Program Files\dotnet\sdk] 2.1.801 [C:\Program Files\dotnet\sdk] 2.1.802 [C:\Program Files\dotnet\sdk] 2.2.401 [C:\Program Files\dotnet\sdk] 2.2.402 [C:\Program Files\dotnet\sdk] 3.0.100 [C:\Program Files\dotnet\sdk] 3.1.102 [C:\Program Files\dotnet\sdk] 3.1.201 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed: Microsoft.AspNetCore.All 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.1.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.2.7 [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 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.1.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.2.7 [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 3.0.0 [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 3.1.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.NETCore.App 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.2.7 [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 3.0.0 [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 3.1.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 3.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.WindowsDesktop.App 3.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 3.1.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 3.1.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

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

Visual Studio Code Extensions

Extension	Author	Version
csharp	ms-dotnettools	1.23.4
debugger-for-chrome	msjsdiag	4.12.11
remote-wsl	ms-vscode-remote	0.50.1
vscode-icons	vscode-icons-team	11.0.0
vscode-pull-request-github	GitHub	0.20.1

[captainsafia]

Yep – this particular issue is resolved.

[captainsafia]

Thanks for reporting this issue, @javsjmoore.

It looks like there was a regression in the code that terminates the application server when the user has stopped debugging. I can take a look at this.