IIS Add Managed Module error after moving from Windows Server 2016 to Windows Server 2022

Question

I updated a VM running Windows Server 2016 to Windows Server 2022.

On Windows Server 2016 I was running ASP.NET 4.7.

After upgrading I get the error below if there is a C-Sharp program (I tested with a Hello, World! script) and I click the Add Managed Module option in IIS.

There was an error while performing this operation.  
  
Details:  
  
Cannot execute a program. The command being executed was 'C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe' /noconfig /fullpaths  
@"C:Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\root\<number>\<number>.cmdline".  

The C-Sharp Compile (csc.exe) is present in the directory.

Any idea how I can diagnose the issue and solve it please?

Answer 1

Hi @chribonn ,

Since the .NET 4.5 version, Roslyn compilation is the default way of compiling. This means if you create any web application either Web Forms or MVC using .NET 4.5 you get this Roslyn csc.exe compilation pre-installed in your project.
Basically what i needed was to compile and deploy my project without Roslyn or any .exe files on it.
A simple solution for this issue is that removing Roslyn compiler plugin from your project and using old compiler. In order to remove Roslyn:

1. “Tools > NuGet Package Manager > Manage NuGet Packages for Solution” in Visual Studio
2. Find “DotNetCompilerPlatform” and uninstall it
   Hope this will solve your purpose. Basically this will not generate any csc.exe, vbc.exe files inside bin folder.

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Best regards,
Yurong Dai

Answer 2

Hi @YurongDaiMSFT-4508 ,

Thanks for your reply.

Is there a way I can achieve the above without installing Visual Studio. The idea is that this machine was not a DEV environment and therefore did not need to have IDEs installed. I would like to avoid this if possible

Thanks

Answer 3

I made a short video to demonstrate what I am getting: https://youtu.be/xZTZJVnFAgw

Is there a way I can disable Roslyn compilation in a simple manner.

Answer 4

Hi @YurongDaiMSFT-4508

The enable 32-Bit Applications to True did not work.

I found the following: disable-roslyn-in-iis-application but I'm not sure this will solve the topic.

Thanks

Answer 5

the roslyn compilers should be in the bin folder. use visual studio publish to build the deployment folder.