IIS Express configuration not working

1. Close Visual Studio

Make sure no instance of Visual Studio or IIS Express is running.

2. Backup & Delete Corrupted Config Files

Navigate to:

%USERPROFILE%\Documents\IISExpress\config

and

C:\Program Files\IIS Express\config\templates\PersonalWebServer

Backup the files somewhere safe.

Delete the following if present:

• applicationhost.config
• aspnet.config
• redirection.config

3. Repair / Reinstall IIS Express ,Go to Apps & Features in Windows and search for IIS Express.

Choose Repair option if Repair is not available, uninstall and then reinstall from: IIS Express 10 Download

4. Restore Default Template Config Files if after reinstall the config files are still missing:

Navigate to:

C:\Program Files\IIS Express\config\templates\PersonalWebServer

Ensure the following exist and are valid XML: 

5. Reset permissions open command prompt as administrator and run as below

icacls "C:\Program Files\IIS Express" /grant Users:(OI)(CI)F /T

This ensures IIS Express can read its config files.

6.Restart your PC and open Visual Studio.

Create a new ASP.NET Web Application (.NET Framework). It should now configure IIS Express successfully.

7.If Visual Studio still shows the error:

Go to Tools → Options → Projects and Solutions → Web Projects

Tick Use the 64-bit version of IIS Express for web sites and projects

Issue caused due to OneDrive sync. After uninstall/reinstall of OneDrive I was able to resolve the issue.

Cause: One Drive unable to sync data. 

Solution: OneDrive is stopping by looking at the internet. You can enable and sync the data. Restart your computer. There are multiple IISExpress folders, one synced to OneDrive and another local. Visual Studio tried to access the OneDrive folder, which was not synced to the local disk, and thus it failed.