Visual Studio updated and will not launch project to any web browser

I have the same problem (same day as you). I was already on the latest version, so it might be another update?

tldr:

manually remove the update KB5066128 using a admin version of CMD:

wusa /uninstall /kb:5066128

this resolves the problem.

I had tried

dism /online /cleanup-image /restorehealth

sfc /scannow

It takes a log time to check all the files. It found some problems, but didn't resolve this problem.

I looked in the event logs and saw this install last night:

Installation Started: Windows has started installing the following update: 2025-10 Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 11, version 25H2 for x64 (KB5066128)

Removing that patch fixes the issue that you can't run debug in any browser.

Thanks for reaching out! Here are some steps which are helpful

1. Check All Output and Log Messages: Check the Output window in Visual Studio for any error messages or clues as to what's happening when you try to launch your project.
2. Verify Browser Debugging Tools:
   • Ensure that your browser (like Edge or Chrome) is set as the default web browser in Visual Studio. You can right-click on your project in Solution Explorer, select "Properties", and check the 'Web' tab for the start action.
3. Reset Visual Studio Settings:
   • Sometimes resetting Visual Studio to its default settings can resolve issues that arise from updates. You can do this by going to Tools > Import and Export Settings > Reset all settings.
4. Reinstall or Repair Visual Studio:
   • If you're still facing issues, consider repairing your Visual Studio installation through the Visual Studio Installer. Sometimes, configurations may get corrupted during updates.
5. Check for Windows Updates:
   • Like Thao suggested, check if there were any recent Windows updates that could affect Visual Studio. Sometimes, rolling back a recent Windows update can help if it’s causing compatibility problems.
6. Run Visual Studio as Administrator:
   • Try running Visual Studio in administrator mode. Right-click the Visual Studio shortcut and select "Run as Administrator."
7. Web Server Configuration:
   • Ensure that your project's web server settings are correct (IIS Express or Kestrel) and that IIS Express isn't encountering issues.
8. Clear Temporary Files:
   • Navigate to the folder where Visual Studio's temporary files are stored and clear them. This is typically located in a path like %LocalAppData%\Microsoft\VisualStudio\<version>\WebApps.