I can't swap to Development Environment

Arin Leviti 60

I published a website on a virtual machine, as it was the only way I could run a small exe console app I wrote on c#. I'ts a small game with inputs and outputs that I adapted to work on the page. When I try the page on my local machine it works fine, but when I click the azure link, I get this message: Error. An error occurred while processing your request. Request ID: 00-b880647b6615cb554652a10e6549f17b-80d41d9feb78848e-00 Development Mode Swapping to the Development environment displays detailed information about the error that occurred. The Development environment shouldn't be enabled for deployed applications. It can result in displaying sensitive information from exceptions to end users. For local debugging, enable the Development environment by setting the ASPNETCORE_ENVIRONMENT environment variable to Development and restarting the app. I tried everything to switch environment on my VM but nothing seems to work. I can't swap to Development. Yesterday this problem simply was not there, and today it appeared out of nowhere...

Accepted answer

Pinaki Ghatak 4,610 Reputation points Microsoft Employee

2024-01-18T14:52:01.8866667+00:00
Hello @Arin Leviti The error message you’re seeing is a common one in ASP.NET Core applications when an unhandled exception occurs. It suggests switching to the Development environment to get more detailed information about the error. To switch the environment on your Azure virtual machine, you can try the following steps:

Set the ASPNETCORE_ENVIRONMENT variable: You can do this in the Azure portal. Go to your Web App’s configuration, find the “Application Settings” section, and add the “ASPNETCORE_ENVIRONMENT” variable with the value "Development".

Modify your Startup.cs file: In the Configure() method of your Startup.cs file, you could try adding app.UseDeveloperExceptionPage();. This will enable the Developer Exception Page when the ASPNETCORE_ENVIRONMENT is set to Development.

Modify your web.config file: If you have a web.config file, you can add an environment variable there. If you don’t have one, you can create one. The environment variable should look like this:

<aspNetCore processPath="dotnet" arguments=".\\YourProjectName.dll" stdoutLogEnabled="false" stdoutLogFile=".\\logs\\stdout"> <environmentVariables> <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" /> </environmentVariables> </aspNetCore>

Remember to replace “YourProjectName” with the actual name of your project. Please note that these steps will expose detailed error messages which can include sensitive information, so they should only be used for debugging. Once you’ve finished debugging, remember to set the ASPNETCORE_ENVIRONMENT variable back to “Production” or another appropriate value. This should get you started.
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4 additional answers

Brando Zhang-MSFT 3,706 Microsoft Vendor

Hi @Arin Leviti,

I tried everything to switch environment on my VM but nothing seems to work. I can't swap to Development.

There is a lot of issue which caused the asp.net core page doesn't work well. To troubleshooting the issue, we need to get the details error message. The reason why you don't get the details error message is the asp.net core contains the codes which disable the details error message when the environment variable is not the development. As the error message said this is due to show the details error message in the production environment is not security. You could find the codes inside program.cs:

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

If you want to see the details error message, you could follow below steps: 1.If you host the application inside the IIS, you could directly find the details error message inside the event viewer's application tag. If you want to enable the development environment variable to see the details error message, you could set below settings inside the web.config.

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <location path="." inheritInChildApplications="false">
    <system.webServer>
      <handlers>
        <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />
      </handlers>
      <aspNetCore processPath="dotnet" 
      arguments=".\WebApplication1.dll" stdoutLogEnabled="false"  stdoutLogFile=".\logs\stdout" hostingModel="inprocess">
      <environmentVariables>
    <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" />
    </environmentVariables>
       </aspNetCore>
    </system.webServer>
  </location>
</configuration>

2.If you running the application directly by using the cmd. I suggest you could try below codes in cmd: dotnet WebApplication1.dll --environment=Development

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Arin Leviti 60

I managed to modify my default page and forced it to show the error. Basically the page can't find the file. The logic works on my local machine when it opens FINAL BATTLE from my computer. This changes for some reason on Azure. Here's the page that runs the Game Logic:

namespace MyWebsite.Pages.FinalBattle
{
    public class GameService : PageModel
    {
        private Process _gameProcess;
        private StringBuilder _outputBuffer = new StringBuilder();

        public void StartGame()
        {
            string gameExecutablePath = /*@"C:\Users\iparalyze\Desktop\ExecutablesDesktop\FINAL BATTLE.exe"*/ @"C:\inetpub\executables\FINAL BATTLE";
			//string gameExecutablePath = null;

   //         if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
   //         {
   //             gameExecutablePath = @"C:\inetpub\executables\FINAL BATTLE.exe"; /*@"C:\Users\alevi\Documents\C#Exercises\FINAL BATTLE BUILDS\FINAL BATTLE.exe"*/
   //         }
   //         else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
   //         {
   //             gameExecutablePath = @"C:\Users\alevi\Documents\C#Exercises\FINAL BATTLE BUILD MAC\FINAL BATTLE";
   //         }
   //         else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
   //         {
   //             gameExecutablePath = @"C:\Users\alevi\Documents\C#Exercises\FINAL BATTLE BUILD LINUX\FINAL BATTLE";
   //         }

            //Within the Process class, there is a property named StartInfo. This property is of the type ProcessStartInfo. It encapsulates several properties that are used when you start a process.
            _gameProcess = new Process
            {
                StartInfo = new ProcessStartInfo
                {
                    FileName = gameExecutablePath,
                    WorkingDirectory = /*@"C:\Users\iparalyze\Desktop\ExecutablesDesktop"*/ @"C:\inetpub\executables" /*@"C:\Users\alevi\Documents\C#Exercises\FINAL BATTLE BUILDS"*/,
                    RedirectStandardInput = true,
                    RedirectStandardOutput = true,
                    UseShellExecute = false,
                    CreateNoWindow = true
                }
            };

            _gameProcess.Start();
			//The OutputDataReceived event is a pre-existing event in the Process class of the .NET Framework.
			//OutputDataReceived is an event of the type DataReceivedEventHandler so OutputDataReceived and the lambda exp. need to have the same signature.
			//When the event is invoked, do the lambda.
			//the signature of the event OutputDataReceived is not EventHandler, but it's DataReceivedEventHandler , with signature (object sender, DataReceivedEventArgs e).
			//DataReceivedEventArgs derives from the class EventArgs. It's specifically designed to provide data for the OutputDataReceived event.
			//This invocation is part of the encapsulated behavior of the Process class. As a developer, you don't see the actual Invoke call;
			//you only subscribe to the event and provide an event handler.
			//the args parameter is an instance of the DataReceivedEventArgs and its property Data contains the data that Final Battle has outputted.
			//The lambda expression is the actual event handler. When the event is raised, _gameProcess passes itself as the sender parameter to this handler.
			//This is a convention in .NET event handling: the object raising the event sends itself as the sender.
			_gameProcess.OutputDataReceived += (sender, args) =>
            {
                if (!string.IsNullOrEmpty(args.Data))
                {
                    _outputBuffer.AppendLine(args.Data);
                }
            };
            // This method allows your application to continuously monitor and react to the output.
            //It's essential for real-time applications where you need to process output as soon as it's available.
            //Without calling this method, even though you have attached an event handler to OutputDataReceived, the event would not be triggered because the stream reading hasn't started.
            // is an implementation of the EAP, which predates the async/await pattern. EAP relies on events to signal the completion of asynchronous operations.
            _gameProcess.BeginOutputReadLine();
        }

        //does not capture input directly from the user interface. 
        //It is used to send a command (which it receives as an input parameter) to the game process. 
        //The WriteLine function within SendCommand writes the command to the standard input of the game process, not to the user interface.
        //This allows the game process to receive and process the command as if it was entered directly in a console window.
        public void SendCommand(string command)
        {
            _gameProcess.StandardInput.WriteLine(command);
            _gameProcess.StandardInput.Flush();
        }

        //It converts the entire content of _outputBuffer (which has been accumulating output lines) into a single string and returns it.
        //called when you want to retrieve all the accumulated output to display it on the user interface.
        public string GetOutput()
        {
            return _outputBuffer.ToString();
        }
        // If the buffer isn't cleared, the output retrieved by subsequent calls to GetOutput would include old data that has already been processed or displayed.
        //
        public void ClearOutputBuffer()
        {
            _outputBuffer.Clear();
        }
        public void StopGame()
        {
            if (_gameProcess != null && !_gameProcess.HasExited)
            {
                _gameProcess.Kill();
                _gameProcess.Dispose();
            }
        }
    }
}

Error Details:

Brando Zhang-MSFT 3,706 Reputation points Microsoft Vendor

2024-01-22T08:07:58.2166667+00:00

Actually, we need to know where you host your application inside the Azure web apps or the Azure VM. If you are using the Azure web apps, you need to modify the file path to match the Azure web apps path, Azure web apps path if different than the local path. You should use IHostingEnvironment.WebRootPath to get the root path instead of static file path like local environment.

Bruce (SqlWork.com) 66,706 Reputation points

2024-01-17T17:31:38.1333333+00:00

development mode will only work if you implemented code to support extra reporting in development mode.

if (app.Environment.IsDevelopment())

in later versions of the framework there may be some default support.
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Arin Leviti 60 Reputation points

2024-01-18T08:33:49.3166667+00:00

I tried both options and nothing's changed...
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Brando Zhang-MSFT 3,706 Reputation points Microsoft Vendor

2024-01-18T08:36:59.18+00:00

Do you facing the error now? and how you host the application?
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Arin Leviti 60

I managed to bypass the Environment modifying the Error page like this: but the problem remains. Error Details:

System.ComponentModel.Win32Exception (2): An error occurred trying to start process 'C:\inetpub\executables\FINAL BATTLE' with working directory 'C:\inetpub\executables'. The system cannot find the file specified.

@page @model MyWebsite.Pages.ErrorModel 
@{     ViewData["Title"] = "Error"; }  
<h1 class="text-danger">Error.</h1> <h2 class="text-danger">An error occurred while processing your request.</h2>  
@if (Model.ShowRequestId) {     
<p>         <strong>Request ID:</strong> <code>@Model.RequestId</code>     </p> }  
@if (!string.IsNullOrEmpty(Model.ErrorMessage)) {     
<h3 class="text-danger">Error Details:</h3>     
<pre>@Model.ErrorMessage</pre> }

using System.Diagnostics;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.AspNetCore.Diagnostics;

namespace MyWebsite.Pages
{
	[ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
	[IgnoreAntiforgeryToken]
	public class ErrorModel : PageModel
	{
		public string ErrorMessage { get; set; }
		public string RequestId { get; set; }
		public bool ShowRequestId => !string.IsNullOrEmpty(RequestId);

		public void OnGet()
		{
			RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier;

			var exceptionFeature = HttpContext.Features.Get<IExceptionHandlerPathFeature>();
			if (exceptionFeature != null)
			{
				// Retrieve the error message
				ErrorMessage = exceptionFeature.Error.ToString(); // Using ToString() to get the full exception details
			}
		}
	}
}

Arin Leviti 60

using Microsoft.AspNetCore.Mvc.RazorPages;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Text;
using static System.Net.WebRequestMethods;

namespace MyWebsite.Pages.FinalBattle
{
    public class GameService : PageModel
    {
        private Process _gameProcess;
        private StringBuilder _outputBuffer = new StringBuilder();

        public void StartGame()
        {
            string gameExecutablePath = @"C:\inetpub\executables\FINAL BATTLE";/*@"C:\Users\iparalyze\Desktop\ExecutablesDesktop\FINAL BATTLE.exe"*/
            //string gameExecutablePath = null;

            //         if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            //         {
            //             gameExecutablePath = @"C:\inetpub\executables\FINAL BATTLE.exe"; /*@"C:\Users\alevi\Documents\C#Exercises\FINAL BATTLE BUILDS\FINAL BATTLE.exe"*/
            //         }
            //         else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
            //         {
            //             gameExecutablePath = @"C:\Users\alevi\Documents\C#Exercises\FINAL BATTLE BUILD MAC\FINAL BATTLE";
            //         }
            //         else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
            //         {
            //             gameExecutablePath = @"C:\Users\alevi\Documents\C#Exercises\FINAL BATTLE BUILD LINUX\FINAL BATTLE";
            //         }

            //Within the Process class, there is a property named StartInfo. This property is of the type ProcessStartInfo. It encapsulates several properties that are used when you start a process.
            _gameProcess = new Process
            {
                StartInfo = new ProcessStartInfo
                {
                    FileName = gameExecutablePath,
                    WorkingDirectory = @"C:\inetpub\executables",/*@"C:\Users\iparalyze\Desktop\ExecutablesDesktop"*/  /*@"C:\Users\alevi\Documents\C#Exercises\FINAL BATTLE BUILDS"*/
                    RedirectStandardInput = true,
                    RedirectStandardOutput = true,
                    UseShellExecute = false,
                    CreateNoWindow = true
                }
            };

            _gameProcess.Start();
			//The OutputDataReceived event is a pre-existing event in the Process class of the .NET Framework.
			//OutputDataReceived is an event of the type DataReceivedEventHandler so OutputDataReceived and the lambda exp. need to have the same signature.
			//When the event is invoked, do the lambda.
			//the signature of the event OutputDataReceived is not EventHandler, but it's DataReceivedEventHandler , with signature (object sender, DataReceivedEventArgs e).
			//DataReceivedEventArgs derives from the class EventArgs. It's specifically designed to provide data for the OutputDataReceived event.
			//This invocation is part of the encapsulated behavior of the Process class. As a developer, you don't see the actual Invoke call;
			//you only subscribe to the event and provide an event handler.
			//the args parameter is an instance of the DataReceivedEventArgs and its property Data contains the data that Final Battle has outputted.
			//The lambda expression is the actual event handler. When the event is raised, _gameProcess passes itself as the sender parameter to this handler.
			//This is a convention in .NET event handling: the object raising the event sends itself as the sender.
			_gameProcess.OutputDataReceived += (sender, args) =>
            {
                if (!string.IsNullOrEmpty(args.Data))
                {
                    _outputBuffer.AppendLine(args.Data);
                }
            };
            // This method allows your application to continuously monitor and react to the output.
            //It's essential for real-time applications where you need to process output as soon as it's available.
            //Without calling this method, even though you have attached an event handler to OutputDataReceived, the event would not be triggered because the stream reading hasn't started.
            // is an implementation of the EAP, which predates the async/await pattern. EAP relies on events to signal the completion of asynchronous operations.
            _gameProcess.BeginOutputReadLine();
        }

        //does not capture input directly from the user interface. 
        //It is used to send a command (which it receives as an input parameter) to the game process. 
        //The WriteLine function within SendCommand writes the command to the standard input of the game process, not to the user interface.
        //This allows the game process to receive and process the command as if it was entered directly in a console window.
        public void SendCommand(string command)
        {
            _gameProcess.StandardInput.WriteLine(command);
            _gameProcess.StandardInput.Flush();
        }

        //It converts the entire content of _outputBuffer (which has been accumulating output lines) into a single string and returns it.
        //called when you want to retrieve all the accumulated output to display it on the user interface.
        public string GetOutput()
        {
            return _outputBuffer.ToString();
        }
        // If the buffer isn't cleared, the output retrieved by subsequent calls to GetOutput would include old data that has already been processed or displayed.
        //
        public void ClearOutputBuffer()
        {
            _outputBuffer.Clear();
        }
        public void StopGame()
        {
            if (_gameProcess != null && !_gameProcess.HasExited)
            {
                _gameProcess.Kill();
                _gameProcess.Dispose();
            }
        }
    }
}

Brando Zhang-MSFT 3,706 Reputation points Microsoft Vendor

2024-01-22T07:58:25.4766667+00:00

According to your other thread, we have seen you publish the application to the https://mywebsite20240115140220.azurewebsites.net/FinalBattle, this url is a Azure web apps url. Could you please confirm you published the application to an Azure web apps not an Azure VM? Azure web apps settings is different than the Azure VM and the path and environment settings is also different than the Azure VM and local development. Since you want to run a specific exe inside the Azure web apps, you need confirm the path and the permission is enough to run it. The path for the Azure web apps is different than the local development environment. And for settings the development variable in Azure web apps, you should follow this article.

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