FileStream - Path found in console-application but not in mvc

Question

Iv'e used this guide drive quickstart and successfully got it worked in a console-app.

Now I'm trying to do the same thing in an mvc-application, but I got error when creating a new FileStream.

The code a use is exactly the same in mvc instead this time i'ts triggered by a button-click. This is my code:

        using (var stream = new FileStream("client_secret.json", FileMode.Open, FileAccess.Read))
        {
            string credPath = System.Environment.GetFolderPath(
                    System.Environment.SpecialFolder.Personal);
            credPath = Path.Combine(credPath, ".credentials/drive-dotnet-quickstart.json");

            credential = GoogleWebAuthorizationBroker.AuthorizeAsync(   
                    GoogleClientSecrets.Load(stream).Secrets,
                    Scopes,
                    "user",
                    CancellationToken.None,
                    new FileDataStore(credPath, true)).Result;
            Console.WriteLine("Credential file saved to: " + credPath);
        }

        // Create Drive API service.
        var service = new DriveService(new BaseClientService.Initializer()
        {
            HttpClientInitializer = credential,
            ApplicationName = ApplicationName,
        });

        // Define parameters of request.
        FilesResource.ListRequest listRequest = service.Files.List();
        listRequest.PageSize = 10;
        listRequest.Fields = "nextPageToken, files(id, name)";

        // List files.
        IList<Google.Apis.Drive.v3.Data.File> files = listRequest.Execute()
                .Files;

I got error at 'using (var stream = new FileStream("client_secret.json", FileMode.Open, FileAccess.Read))'

My 'client_secret.json'-file is stored at the root of my mvc project. And I've done the step: Select client_secret.json, and then go to the Properties window and set the Copy to Output Directory field to Copy always.

Why is this not working in my mvc-app?

The error I get is 'System.IO.FileNotFoundException' - '{"Cannot find file c:\windows\system32\inetsrv\client_secret.json.":"c:\windows\system32\inetsrv\client_secret.json"}'