Application_start event not firing in server, but works just fine in debug.

Anish Soman 20

We have an .net framework web application running on IIS 10. I've added some code in the Application_start method of Global.asax.cs and it's not getting fired at all in the server. This is working just fine in debug using visual studio 2022 using target framework 4.6 Build machine is also using visual studio 2022, and the target framework in server is also 4.6. . It's not just Application_start and looks like no event in Global.asax.cs is being fired. We have some methods in Application_Error to capture the uncaught exception and to show a user friendly error message. That also is not working.

Interesting part is that this worked a few months ago. After that there were no changes to Global.asax or Global.asax.cs.

We can't debug on server since there is no Visual Studio installed there. Any guidance on what could be wrong or any way to identify the issue is appreciated.

Thanks in Advance.

Sam Wu-MSFT 7,526 Reputation points Microsoft Vendor

2024-10-08T07:58:57.6866667+00:00

@Anish Soman

You can try to use IIS's tracing capabilities or ASP.NET's health monitoring to identify whether requests are reaching your application and what happens after they are processed. enable IIS tracing to monitor application events and failures, which might give you more details on what's going wrong.
AgaveJoe 28,371 Reputation points

2024-10-08T12:22:44.2966667+00:00

I'm sure the Application_Start event is firing. Most likely there is an problem with the event handler. Can you give us some insight on how you are testing the Application_Start handler and how you know the handler is not firing? Did you add application configuration that is not functioning as expected? Is there anyway you can provide the source code so we can see what's going on?

Anish Soman 20

@Sam Wu-MSFT & @AgaveJoe Requests are reaching Application because I'm getting a YSOD. I added a log write in the Application_start event handler, based on a config flag and turned the flag on. I don't get any log entries.

Application_Start handler is as below. The log write (the absence of the log entry) tells me that the code was never invoked.

protected void Application_Start(Object sender, EventArgs e)         
{              
  Version version;             
  version = Assembly.GetExecutingAssembly().GetName().Version;
  Application["Version"] = version.Major + "." + version.Minor + "." + version.Build 
  +  "." + version.Revision;
             
  string useVault = Convert.ToString(ConfigurationManager.AppSettings["UseVault"]); 
  if (useVault == "Y") 
  {                 
     AlternateLogger alternateLogger = new AlternateLogger();
     /*Log Write*/
     alternateLogger.WriteLogAlt("Use Vault", "Application_Start", "Global.asax");
     GetCredsFromVault();  /*New method to access HashiCorp Vault  */ 
   }         
}

Also, I've Application_Error handler that sends a custom error page. I shouldn't get the YSOD if the Global.asax events were fired.

AgaveJoe 28,371 Reputation points

2024-10-08T19:00:15.6766667+00:00

I'm confused... Is the actual problem you are trying to debug the yellow screen of death (YSOD)? Usually the yellow screen of death has a lot of information like the line of code that cause the exception when custom errors is turned off in the web.config.

https://learn.microsoft.com/en-us/dotnet/api/system.web.configuration.customerror?view=netframework-4.8.1
Lex Li (Microsoft) 5,582 Reputation points Microsoft Employee

2024-10-08T20:59:38.96+00:00
How did you deploy the web app to IIS after verifying in VS? If CI/CD is used, can you copy the assemblies out of the production machine, decompile them and confirm the code changes are actually included? It's very important to rule out deployment issues first.

Like another comment indicated, any .NET Framework 4.x releases older than 4.6.2 are now end of life, so on your production machine you must run the bits with .NET Framework 4.6.2 and above. You can upgrade and rule out compatibility issues.
Sam Wu-MSFT 7,526 Reputation points Microsoft Vendor

2024-10-09T02:56:37.8933333+00:00

@@Anish Soman

Check if the Global.asax and Global.asax.cs files exist on the server in the root of the application directory. If not, redeploy them, because this problem may occurs when Global.asax or its code files are not correctly deployed to the server.
Anish Soman 20 Reputation points

2024-10-09T16:47:50.4133333+00:00

@AgaveJoe , I'm not trying to debug the YSOD. I was saying, I'm sure that the requests are reaching the application because I'm getting a YSOD. Since we have code in Application_Error() to throw a error page instead, seeing the YSOD is another indication that the Global.asax.cs not executing.
Anish Soman 20 Reputation points

2024-10-09T16:53:02.1+00:00

@Lex Li (Microsoft) , Yes, CI/CD pipeline was used to deploy the code and the Global.asax is present in the root folder. I'll decompile and see if the changes are there. Regarding the framework, we are using 4.8 to build but targetting 4.6. I'll try to change the targetting framework also to be as 4.8.
Anish Soman 20 Reputation points

2024-10-09T16:55:30.48+00:00

@Sam Wu-MSFT , I see Global.asax in the folder and that's up to date. I don't have a dll with name Global.asax because this is a web app project and we get only one dll per project. As other comment asked, I'll try to decompile the dlls and make sure my code is there.

1 answer

Bruce (SqlWork.com) 65,316 Reputation points

2024-10-08T17:12:45.1666667+00:00

this is generally a permission error on the server. also check you deployed Global.asax and the code behind file is in the build.

note: .net 4.6 is no longer supported. you should see if the issue is reproducible when the server is using .net 4.8
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Anish Soman 20 Reputation points

2024-10-08T18:28:32.77+00:00

@Bruce (SqlWork.com) , What permission I need to grant and to which user? which folder/path?

Bruce (SqlWork.com) 65,316 Reputation points

2024-10-09T21:23:43.08+00:00

don't know what your code does. could be the AlternateLogger or GetCredsFromVault() throw an error.

Anish Soman 20 Reputation points

2024-10-10T21:08:33.1733333+00:00

I might have found the problem but I don't know how to fix. When I debug/publish from VS, the target folder contails App_global.asax.compiled and App_global.asax.dll files, whereas in the CI/CD pipeline deployed folder I don't see those. Pipeline is using MsBuild batch commands to build the solution. I tried the same command in my machine and it don't generate these files.

Here is the command - MsBuild /t:restore "%TF_Directory%%TF_Folder%%TF_SolutionFile%" /t:Clean;Build /p:RunXunitTests=true /p:OutDir=%DestPath% /p:Platform="Any CPU" /p:Configuration=Debug > "%Build_Directory%%Build_LogFile%" 2> "%Build_Directory%%Build_ErrorFile%" "

Please suggest what changes are needed to get MsBuild Command generate the files.

Bruce (SqlWork.com) 65,316 Reputation points

2024-10-10T22:20:49.2033333+00:00

those the precompiled. you need to add the precompile switch to get them:

/p:PrecompileBeforePublish=true

see docs:

https://learn.microsoft.com/en-us/previous-versions/aspnet/aa983464(v=vs.110)

but as long as you deploy the global.asax the aspnet_compiler should compile it. the application dll should have the code behind
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Application_start event not firing in server, but works just fine in debug.

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