使用angularjs模板启动新项目时.Net Core System.Net.Http.HttpRequestException异常

我正在尝试使用

.Net Core

的SPA模板创建angular 2应用程序。为了安装模板，我使用了以下命令

dotnet new --install Microsoft.AspNetCore.SpaTemplates::*

安装完成后，我运行

dotnet new angular

这为我创建了一个新的AngularJS项目。我使用

.csproj

文件在Visual Studio 2017社区版中打开了新项目。然后，我没有调试就运行了应用程序（Ctrl+F5）。
我犯了以下错误

System.AggregateException: One or more errors occurred. (An error occurred while sending the request.) ---> System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.Http.WinHttpException: A connection with the server could not be established
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at System.Net.Http.WinHttpHandler.<StartRequest>d__105.MoveNext()
   --- End of inner exception stack trace ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at System.Net.Http.HttpClient.<FinishSendAsync>d__58.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.NodeServices.HostingModels.HttpNodeInstance.<InvokeExportAsync>d__7`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.NodeServices.HostingModels.OutOfProcessNodeInstance.<InvokeExportAsync>d__14`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.NodeServices.NodeServicesImpl.<InvokeExportWithPossibleRetryAsync>d__10`1.MoveNext()
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at Microsoft.AspNetCore.Builder.WebpackDevMiddleware.UseWebpackDevMiddleware(IApplicationBuilder appBuilder, WebpackDevMiddlewareOptions options)
   at Sample.Startup.Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory) in C:\DotNetCore\Sample\Startup.cs:line 44
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.AspNetCore.Hosting.ConventionBasedStartup.Configure(IApplicationBuilder app)
   at Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication()
---> (Inner Exception #0) System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.Http.WinHttpException: A connection with the server could not be established
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at System.Net.Http.WinHttpHandler.<StartRequest>d__105.MoveNext()
   --- End of inner exception stack trace ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at System.Net.Http.HttpClient.<FinishSendAsync>d__58.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.NodeServices.HostingModels.HttpNodeInstance.<InvokeExportAsync>d__7`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.NodeServices.HostingModels.OutOfProcessNodeInstance.<InvokeExportAsync>d__14`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.NodeServices.NodeServicesImpl.<InvokeExportWithPossibleRetryAsync>d__10`1.MoveNext()<---

System.AggregateException:发生了一个或多个错误。（发送请求时出错。）-->System.Net.Http.HttpRequestException:发送请求时出错。-->System.Net.Http.WinHttpException:无法建立与服务器的连接
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
在System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult（）中
在System.Net.Http.WinHttpHandler.d_u105.MoveNext（）中
---内部异常堆栈跟踪的结束---
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
在System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult（）中
在System.Net.Http.HttpClient.d_u58.MoveNext（）上
---来自引发异常的上一个位置的堆栈结束跟踪---
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
位于Microsoft.AspNetCore.NodeServices.HostingModels.HttpNodeInstance.d_u7`1.MoveNext（）
---来自引发异常的上一个位置的堆栈结束跟踪---
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
位于Microsoft.AspNetCore.NodeServices.HostingModels.OutOfProcessNodeInstance.d_u14`1.MoveNext（）
---来自引发异常的上一个位置的堆栈结束跟踪---
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
在Microsoft.AspNetCore.NodeServices.nodeservicesimple.d_u10`1.MoveNext（）中
---内部异常堆栈跟踪的结束---
位于System.Threading.Tasks.Task.ThrowifeException（布尔值IncludeTaskCanceledException）
位于System.Threading.Tasks.Task`1.GetResultCore（布尔waitCompletionNotification）
在Microsoft.AspNetCore.Builder.WebpackDevMiddleware.UseWebpackDevMiddleware（IApplicationBuilder appBuilder，WebpackDevMiddlewareOptions选项）中
在C:\DotNetCore\Sample\Startup.cs中的Sample.Startup.Configure（IAApplicationBuilder应用程序、IHostingEnvironment环境、ILoggerFactory loggerFactory）处：第44行
---来自引发异常的上一个位置的堆栈结束跟踪---
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
位于Microsoft.AspNetCore.Hosting.ConventionBasedStartup.Configure（IApplicationBuilder应用程序）
在Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication（）上
--->（内部异常#0）System.Net.Http.HttpRequestException:发送请求时出错。-->System.Net.Http.WinHttpException:无法建立与服务器的连接
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
在System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult（）中
在System.Net.Http.WinHttpHandler.d_u105.MoveNext（）中
---内部异常堆栈跟踪的结束---
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
在System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult（）中
在System.Net.Http.HttpClient.d_u58.MoveNext（）上
---来自引发异常的上一个位置的堆栈结束跟踪---
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
位于Microsoft.AspNetCore.NodeServices.HostingModels.HttpNodeInstance.d_u7`1.MoveNext（）
---来自引发异常的上一个位置的堆栈结束跟踪---
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
位于Microsoft.AspNetCore.NodeServices.HostingModels.OutOfProcessNodeInstance.d_u14`1.MoveNext（）
---来自引发异常的上一个位置的堆栈结束跟踪---
在System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）中
在System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务）中
在Microsoft.AspNetCore.NodeServices.nodeservicesiml.d_u10`1.MoveNext（）中，根据此初始异常源：

Microsoft.AspNetCore.NodeServices.NodeServicesImpl.<InvokeExportWithPossibleRetryAsync>d__10`1.MoveNext()<---

Microsoft.AspNetCore.NodeServices.nodeservicesiml.d_u10`1.MoveNext（）根据此初始异常源：

Microsoft.AspNetCore.NodeServices.NodeServicesImpl.<InvokeExportWithPossibleRetryAsync>d__10`1.MoveNext()<---

Microsoft.AspNetCore.NodeServices.nodeservicesimple.d_u10`1.MoveNext（）我试图在本地运行此程序，并且在安装
Node.js
后重新启动了我的计算机。我可以从控制台运行其他
Node.js
应用程序。异常消息表示无法建立连接。这要么是网络问题，要么是node.js启动问题看起来确实如此。我无法诊断问题，这使我很难找到解决方案！是否有任何方法可以验证/确认这是Node.js的问题