FileVersionInfo returns the wrong version when exe is changed

Question

I have a scenario where an application update may be installed by one user, while the application is running for another logged-in user.

When the other user reconnects to their session, a call to FileVersionInfo.GetVersionInfo(file) is used to check if an update has occurred and is intended to restart the application.

However, although the file in File Explorer displays the new version number (same version used for both file and product version), the call to GetVersionInfo() returns the current executing version - not the one on disk.

I am setting only the [assembly: AssemblyVersion("A.B.C.D")] version attribute, and leaving the others undefined such that they default to the AssemblyVersion value.

string file = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, AppDomain.CurrentDomain.FriendlyName);
/// or
string file = @"C:\Program Files (x86)\Company\Product\product.exe";

FileVersionInfo info = FileVersionInfo.GetVersionInfo(file);
info.FileVersion; /// returns 1.0.0.0

However the File Version (and Product Version) details for product.exe in File Explorer indicate 2.0.0.0.

I think the executing assembly must be referencing some sort of virtualized file or a path in the VirtualStore because the file system has changed.

How can I reliably get the actual File Version as it appears for product.exe in my C:\Program Files (x86)\Company\Product directory?

---

To reproduce this, use the following Console application:

using System;
using System.Diagnostics;
using System.IO;

namespace versiontest
{
    class Program
    {
        static void Main(string[] args)
        {
            string file = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, AppDomain.CurrentDomain.FriendlyName);
            Console.WriteLine("Getting FileVersion of {0}: {1}", file, FileVersionInfo.GetVersionInfo(file).FileVersion);

            Console.WriteLine("Modify the file and press any key to continue...");
            Console.ReadKey();

            Console.WriteLine("Getting FileVersion of {0}: {1}", file, FileVersionInfo.GetVersionInfo(file).FileVersion);

            Console.WriteLine("Press any key to exit...");
            Console.ReadKey();
        }
    }
}

Build two versions of the application. The first should have the assembly version attribute, with no other version attributes, set in AssemblyInfo.cs as:

[assembly: AssemblyVersion("1.0.0.0")]

The second should have the version set as

[assembly: AssemblyVersion("2.0.0.0")]

Execute the version 1.0.0.0 app.exe, then after the first file version is retrieved, rename the executing app.exe to app.exe.bak and copy the version 2.0.0.0 app.exe into the same folder.

When I do this, this is my console output:

Getting FileVersion of C:\Users\User\Documents\Company\Source\product\testapp\bin\x86\Debug\app.exe: 1.0.0.0
Modify the file and press any key to continue...
Getting FileVersion of C:\Users\User\Documents\Company\Source\product\testapp\bin\x86\Debug\app.exe: 1.0.0.0
Press any key to exit...

If you run app.exe again immediately, being the version 2.0.0.0 application, the console output will show:

Getting FileVersion of C:\Users\User\Documents\Company\Source\product\testapp\bin\x86\Debug\app.exe: 2.0.0.0