Unable to start IIS Express after updating Windows 11 update 24H2 - VS 2022 Professional (64 bit)

Question

Hi Team,

I am facing issue with IIS Express after updating to Windows 24H2, starting a web application in Visual Studio with .NET Framework 4.8 or 4.8.1 shows the error:

Error Message:

"Unable to start program Files\IIS Express\iisexpress.exe.

The process has been terminated.

Refresh the process list before attempting another attach."

I’ve tried however it didn’t fix the issue:

1. Repair IIS Express installation
2. Uninstall and reinstall IIS Express
3. Delete some folders (.vs - bin - obj) and rebuild the solution
4. Repair Visual Studio Installation from Visual Studio Installer
5. Uninstall and reinstall Visual Studio from Visual Studio Installer

But it is working, if reverted the windows update

VS: Professional 2022 Version 17.12.4
OS update: Windows 11, Version 24H2
Framework Update: Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 11, version 22H2 and Windows 11, version 23H2
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** Seems the issue is with 32- and 64-bit version related, because

if I unselect VS IDE below option

Use the 64-bit version of IIS Express for web sites and projects, unable to start IIS express error is gone **

Answer 1

Hi @Ramesh Sivaperumal , 

Welcome to Microsoft Q&A! 

You can try to right-click on project node in the Solution Explorer > Properties > Build > check the box for "Prefer 32-bit". 

If it doesn’t work, I suspect it is a compatibility issue between IIS Express and Windows 11 version 24H2. I found you have reported it in Developer Community.

Unable to start IIS Express on Visual Studio 2022 professional after updating Windows 11 - Developer Community 

Please be patient and wait for a response from the product team. Thanks for your understanding. 

Sincerely,

Anna

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