Recently, I'm facing a strange issue while hosting .net core 2.2 application on IIS.
After hosting, I get "An error occurred while starting the application". In order to identify the root cause I enabled the log file and found that its because of environment variable issue.
I configured the environment variable in my web.config file as like below,
<aspNetCore processPath="dotnet" arguments=".\PctrClient.Api.dll" stdoutLogEnabled="true" stdoutLogFile=".\logs\stdout" hostingModel="InProcess">
<environmentVariables>
<environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" />
</environmentVariables>
</aspNetCore>
Program.cs
public class Program
{
public static void Main(string[] args)
{
CreateWebHostBuilder(args).Build().Run();
}
public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>()
.UseIISIntegration();
}
But web app interprets it as Development;Development. How is it possible?
Info from log file
info Hosting environment: Development;Development
i have got problems about IIS and i changed applicationHost.config with tags. now i can use same IIS with different env. for each web app.
In order to resolve this issue, we have to set the environment variable either in system level or in web.config file. (if we set the environment variable in both places, it will get appended by .net core 2.2 framework)
From my perspective, it looks like a strange behavior, so I have raised this issue in GitHub/AspNetCore to know other community users thoughts, hope this issue will get addressed soon.
I did 2 projects to test out NLog on a .NET Framework 4.6.1 standard console app and on .NET Standard 2.0 Library. My intention is to port as much code as I can to .NET Standard 2.0 for future multiplatform compatibility.
Both share the same code but the .NET Standard version produces an exception.
Here's the code
Console.WriteLine("Writing log");
Logger _errorLog = LogManager.GetLogger("ErrorsLogger");
Logger _tradesLog = LogManager.GetLogger("TradesLogger");
_errorLog.Error("This is the log message!!!");
Console.WriteLine("End log");
Console.Read();
Here's the App.Config
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<section name="nlog" type="NLog.Config.ConfigSectionHandler, NLog"/>
</configSections>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<targets>
<target name="ErrorsLogger" xsi:type="File" fileName="ErrorsLog.txt" />
<target name="TradesLogger" xsi:type="File" fileName="TradesLog.txt" />
</targets>
<rules>
<logger name="ErrorsLogger" minlevel="Info" writeTo="ErrorsLogger" />
<logger name="TradesLogger" minlevel="Info" writeTo="TradesLogger" />
</rules>
</nlog>
</configuration>
I get the log fine in the .NET 4.6.1 Console app and produces the expected log file with the log message in it.
If I run the .NET Standard 2.0 library through some Microsoft Unit Test project I get this exception when it tries to call _errorLog.GetLogger
UnitTestProject.UnitTest1.TestMethod1 threw exception:
System.TypeInitializationException: The type initializer for
'NLog.LogManager' threw an exception. --->
System.TypeInitializationException: The type initializer for
'NLog.LogFactory' threw an exception. --->
System.MissingMethodException: Method not found:
'System.AppDomainSetup System.AppDomain.get_SetupInformation()'.
EDIT:
Nuget NLOG Version: 4.4.12
Exception thrown in a non static method:
About the non static method to get a better exception:
The exception is thrown at the GetLogger("X") level, which is a non static constructor. The initialization routine crashes even before trying to log something.
In addition, I get a WARNING (yellow exclamation mark) in the error list saying:
Warning The 'configuration' element is not declared.
Adding internal logging doesn't produce any output. This is the configuration i have used, starting from their Internal logging guide:
InternalLogger.LogLevel = LogLevel.Trace;
InternalLogger.LogFile = #"C:\temp\int.txt";
InternalLogger.LogToConsole = true;
InternalLogger.LogToConsoleError = true;
InternalLogger.LogWriter = new StringWriter(new StringBuilder());
InternalLogger.LogToTrace = true;
LogManager.ThrowConfigExceptions = true;
LogManager.ThrowExceptions = true;
Logger logger = LogManager.GetLogger("foo");
I'm administrator and Visual Studio 2017 is started as administrator and I have permission to write in C:\temp ad .NET 4.6.1 console application is able to write in that folder and it's in the same project.
The internal log file is empty and the Unit test project runs the test successfully.
I have no clue of what is happening. No error is thrown now.
Any suggestion to debug the issue is welcome.
An ISSUE on GitHub is already opened.
HERE is a test solution that I made to show you (PASSWORD: logging123). Now that I've updated to Nlog 4.5 you will see that the .NET framework solution throws an error trying to get an old version of Nlog (that I've never referenced) and that .NET Core unit test solution works but doesn't produce any file.
I was experiencing the same issue though I was running .NET 4.7. I updated my NLog package from 4.4.12 to 4.5.0-rc04 and it worked. Knowing its pre-release you may want to be cautions about putting it on live environment though.
Your zipped solution is password protected, so now it is just me guessing, but it looks like you are using app.config to hold nlog.config.
Pretty sure app.config are not being used by NetCoreApps. Try to put your Nlog-config in a separate file called nlog.config and make sure it is Copy Always (In Visual Studio File Properties).
I've got an NLog configuration which works just fine for my web app (ASP.NET Core).
Now I'm trying to add NLog to my webjobs, but I can't figure out how to do it.
In Program.cs within the webjob project, I need to somehow inject IHostingEnvironment and ILoggerFactory (Both of which I inject into the StartUp constructor of the web app).
Once I know how to do that, I should be able to finish off the configuration.
If that's not possible, what alternatives do I have?
I'm not keen to use the TextWriter class passed into the webjob methods, as I imagine it would be difficult to extract the logs and route them to where I ultimately want it to go.
Following are steps of using NLog in WebJob.
Step 1, install NLog.Config package for your WebJob.
Install-Package NLog.Config
Step 2, add rules and targets to NLog.config files. Following is the sample of writing logs to a file.
<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<targets>
<target name="logfile" xsi:type="File" fileName="file.txt" />
</targets>
<rules>
<logger name="*" minlevel="Info" writeTo="logfile" />
</rules>
</nlog>
Step 3, get logger instance using LogManager class.
private static Logger logger = LogManager.GetLogger("MyLog");
Step 4, after got the logger instance, you could write log using following code.
logger.Trace("Sample trace message");
logger.Debug("Sample debug message");
I followed this article to deploy my ASP.NET MVC Core 1.0 app to local IIS on my Windows 10 that is using IIS 10. The application deployed successfully and it opens the home page fine. I'm using Individual User Accounts Authentication. On the home page when I enter login/password and click Login button, I get the following error. I'm using the latest versions of ASP.NET Core and VS2015. I used VS2015 Publish wizard to publish the app. Everything is done on the same machine:
An error occurred while processing your request.
Development Mode
Swapping to Development environment will display more detailed information about the error that occurred.
Development environment should not be enabled in deployed applications, as it can result in sensitive information from exceptions being displayed to end users. For local debugging, development environment can be enabled by setting the ASPNETCORE_ENVIRONMENT environment variable to Development, and restarting the application.
First, check the value of ASPNETCORE_ENVIRONMENT variable. You will have to set this environment variable to "Production" (or other environment than Development)
Otherwise, you can update web.config like this-
<configuration>
<!--
Configure your application settings in appsettings.json. Learn more at http://go.microsoft.com/fwlink/?LinkId=786380
-->
<system.webServer>
<handlers>
<add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
</handlers>
<aspNetCore processPath=".\Application.exe" arguments="" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" forwardWindowsAuthToken="false">
<environmentVariables>
<environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Production" />
</environmentVariables>
</aspNetCore>
</system.webServer>
</configuration>
Refer this post for more details.
I wanted to run it in development environment, so I added following in web.config file, and it worked for me:
<environmentVariables>
<environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" />
</environmentVariables>
If you are developing using ASP.NET CORE. You can find this setting inside properties and then in launchSetting.json file.
"profiles": {
"IIS Express": {
"commandName": "IISExpress",
"launchBrowser": true,
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Production"
},
"nativeDebugging": false
},
"Ecommerce": {
"commandName": "Project",
"launchBrowser": true,
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Production"
},
"applicationUrl": "https://localhost:5001;http://localhost:5000"
}
}
Change "ASPNETCORE_ENVIRONMENT": "Development" to "ASPNETCORE_ENVIRONMENT": "Production"
You can find the launchSetting.json file by expanding properties
I had the same problem (ASP.NET CORE 3.1) but changing "ASPNETCORE_ENVIRONMENT" did not helped.
Scouring through the web I found that in Startup.cs, Configure method, this code was hiding the real issue.
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
Then I deleted the If block and added Database error pages ( You might need to Install Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore from NuGet )
app.UseDatabserrorPages();
So your Startup.cs will look like this
app.UseDeveloperExceptionPage();
app.UseDatabaseErrorPage();
app.UseHttpsRedirection();
//Others will be Okay
Then you will see the real errors on the webpage. For me it was
Login failed for user IIS APPPOOL\DefaultAppPool
So I had to run a GRANT SCRIPT. I just had to run this script on my SQL Server
IF NOT EXISTS (SELECT name FROM sys.server_principals WHERE name = 'IIS APPPOOL\DefaultAppPool')
BEGIN
CREATE LOGIN [IIS APPPOOL\DefaultAppPool]
FROM WINDOWS WITH DEFAULT_DATABASE=[master],
DEFAULT_LANGUAGE=[us_english]
END
GO
CREATE USER [WebDatabaseUser]
FOR LOGIN [IIS APPPOOL\DefaultAppPool]
GO
EXEC sp_addrolemember 'db_owner', 'WebDatabaseUser'
GO
You can see this link : https://learn.microsoft.com/en-us/aspnet/web-forms/overview/deployment/visual-studio-web-deployment/deploying-to-iis
And my problem was solved. Hope this helps somebody.
There is a runtime exception in code. in Production mode it can not be show. so that it show "Development environment should not be enabled in deployed applications, as it can result in sensitive information from exceptions being displayed to end users"
in web.config file you will find
<aspNetCore processPath="dotnet" arguments=".\PortfolioApp.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" />
replace it with
<aspNetCore processPath=".\Application.exe" arguments="" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" forwardWindowsAuthToken="false">
<environmentVariables>
<environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" />
</environmentVariables>
</aspNetCore>
now you run app in browser. It will show actual error message. Now it's time to fix the runtime exception.
I just replaced this:
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseMigrationsEndPoint();
}
else
{
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();
}
with this:
app.UseDeveloperExceptionPage();
app.UseMigrationsEndPoint();
When your connection string is not correct, you get this error. When I correct my connection string it worked fine.
Eg: for correct azure db connection string
Server={Server Name};Initial Catalog={Database Name};Persist Security Info=False;User ID={DB User Name};Password={your_password};MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;
For me, it was a matter of adding the EnvironmentName property to the pubxml.
https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/visual-studio-publish-profiles?view=aspnetcore-5.0
First, this error occurs where you publish a web site that raises errors in the run-time. So check your code again in the pages that give this error.
Then, set the value of ASPNETCORE_ENVIRONMENT variable to Production (instead of Development), you should also check the layout page and change <environment"development"> to <environment"Production">.
Finally, publish your web site.
This is tested in VS2017
This might not be the case for everyone, however I was trying to deploy a "release" configuration to a server that had an environment variable of "uat". I set up a uat configuration to use with my deployment and the message no longer appeared when navigating to my site url. Long story short, just make sure your intended build configuration matches the destination server as others have alluded to above!
The only way I could get rid of the Development Mode message was to change appsettings.json context from
Integrated Security=True
to specifying
User Id=username;Password=password and making sure the user was a db_owner.
By default, in production, you will see this error page unless you create/customize your own. Depending on the project type, it can be in different places like Pages/Error.razor or as a controller action.
This error message is just a hard-coded text in the Error.cshtml file, not the actual error message, only the RequestID is dynamically generated, but not helpful. It only comes up when you publish it to a production web server, and if there is an error.
The template wizard adds an Error.cshtml and Error.cshtml.cs files to the Pages folder if the project is a Razor Pages while it only adds an Error.cshtml to the Views\Shared folder if the project is MVC. This file was there since ASP.NET Core 2.0, still unchanged.
Code in the Error.cshtml file as follows (ASP.NET Core Razor Pages project):
#page
#model 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>
<p>#Model.</p>
}
<h3>Development Mode</h3>
<p>
Swapping to the <strong>Development</strong> environment displays detailed
information about the error that occurred.
</p>
<p>
<strong>The Development environment shouldn't be enabled for deployed applications.</strong>
It can result in displaying sensitive information from exceptions to end users.
For local debugging, enable the <strong>Development</strong> environment by setting the <strong>ASPNETCORE_ENVIRONMENT</strong> environment variable to <strong>Development</strong>
and restarting the app.
</p>
In the MVC project, the code is the same except first 2 lines, it has only one line, replacing ErrorModel with ErrorViewModel:
#model ErrorViewModel
If there is an error this file will show if the environment is NOT the DEVELOPMENT, while it will show the actual error message in the development environment, based on the code in the Configure method in Startup.cs file. The code below shows for Razor Pages, for MVC only change is the path to the Error file app.UseExceptionHandler("/Home/Error");:
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseDatabaseErrorPage();
}
else
{
app.UseExceptionHandler("/Error");
app.UseHsts();
}
We do not need to change the above code.
So this Development Mode message will come up for any error pops from the application. If you want to show the proper error messages, More information can be found here in the doc.
To avoid confusion, change the original message as shown above, <h3> header and <p> to:
<h3>This is Production Mode </h3>
<p>Contact the developers of the app. If you are the developer swap to the
Development environment to see detailed information about the error that occurred.
</p>
Now if we take a look at the line with <aspNetCore in the Web.config file in your server:
<aspNetCore processPath=".\OurASPNETCoreApplication.exe" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" />
That indicates that this is in production mode by default since it doesn't include the child <environmentVariables> node. Now to change the environment to development change that line to:
<aspNetCore processPath=".\OurASPNETCoreApplication.exe" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" >
<environmentVariables>
<environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" />
</environmentVariables>
</aspNetCore>
and restart the web server. It will show the actual error message.
Most of the time it will be the database configuration errors.
Alternatively use a third-party logging provider, like Serilog to write logs into a text file.
This is an old thread. I didn't find the answer here.
But I found a solution and want to share it.
All worked perfectly on my computer. But when I publish to the web server and open the new page "MyLogin" I get the error. Solution that worked for me:
Delete the "bin" and "obj" folder in the current Project.
Remove all files/folders on the destination folder on the web server.
This is the default error page with generic error message.
I got this error after deploying the ASP.NET Core 3.1 MC published application on shared hosting. Default Home and Privacy pages were working as expected but when I tried to open a page that was fetching data from database the above error shown.
Error reason: In appsettings.json, I updated connection string Data Source=MyPC\MSSQLSERVER14 with Data Source=.\MSSQLSERVER2. I copied this data source ".\MSSQLSERVER2" from shared hosting connection string and pasted it in appsettings.json
Resolution: Changed data source ".\MSSQLSERVER2" to ".\\MSSQLSERVER2".
"ConnectionStrings": { "AppCon": "Data Source=.\\MSSQLSERVER2xxx;Initial Catalog=sqldb;Persist Security Info=True;User ID=sqluser;Password=********" }
I have an on premise service bus that is configured to handle messages from an azure queue. The problem i am having is that the host is reporting an msmq error saying that it could not create the error queue. Aside from the fact that it should not be using msmq, it also handles the messages with no problems despite the error so it does not seem to be critical.
My Host is running as a class library configured to start with the nservicebus.host.exe process.
Here is my host code and config:
internal class EndpointConfig : IConfigureThisEndpoint, AsA_Server, IWantCustomInitialization
{
#region IWantCustomInitialization Members
public void Init()
{
Configure.With()
.DefaultBuilder()
.AzureMessageQueue()
.JsonSerializer()
.UnicastBus()
.IsTransactional(true)
.InMemorySubscriptionStorage();
}
#endregion
}
Config:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="UnicastBusConfig" type="NServiceBus.Config.UnicastBusConfig, NServiceBus.Core" />
<section name="AzureQueueConfig" type="NServiceBus.Config.AzureQueueConfig, NServiceBus.Azure"/>
<section name="MessageForwardingInCaseOfFaultConfig" type="NServiceBus.Config.MessageForwardingInCaseOfFaultConfig, NServiceBus.Core" />
</configSections>
<MessageForwardingInCaseOfFaultConfig ErrorQueue="error" />
<AzureQueueConfig QueueName="sender" ConnectionString="UseDevelopmentStorage=true" PeekInterval="5000" MaximumWaitTimeWhenIdle="60000" />
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedruntime version="v4.0" />
<requiredruntime version="v4.0.20506" />
</startup>
</configuration>
And Here is the actual Error Message:
2012-04-24 07:57:10,973 [1] ERROR NServiceBus.Utils.MsmqUtilities [(null)] <(nul
l)> - Could not create queue error#UseDevelopmentStorage=true or check its exist
ence. Processing will still continue.
System.Messaging.MessageQueueException (0x80004005): Message Queue service is no
t available.
at System.Messaging.MessageQueue.Create(String path, Boolean transactional)
at NServiceBus.Utils.MsmqUtilities.CreateQueue(String queueName, String accou
nt)
at NServiceBus.Utils.MsmqUtilities.CreateQueueIfNecessary(Address address, St
ring account)
EDIT: Adding .MessageForwardingInCaseOfFault() to the initialization corrected the issue.
Looks like AsA_Server assumes msmq, guess you'll have to configure the process manually
Adding .MessageForwardingInCaseOfFault() to the init method resolved the issue. Still feels like there is an underlying bug, but it is working.
I suspect that below described the next hurdle (not handling errors correctly) but i will have to try to force a failed message to verify.
As described in:
NServiceBus error queues in Azure