ASP.net app crashes - Could not load file or assembly 'Microsoft.Threading.Tasks.Extensions.Desktop'

Question

I want to build a Google BigQuery C# ASP.net application using OAuth2 and the .Net 4.5 framework. I ran these NuGet installs

Install-Package Google.Apis.Bigquery.v2 -Pre
Install-Package Google.Apis.Authentication.OAuth2 -Version 1.2.4696.27634

Install-Package Google.Apis -Pre
Install-Package Google.Apis.Auth -Pre

and I placed the relevant "usings" in code-behind file "default.aspx.cs":

using System;
using System.Collections.Generic;
using System.IO;
using System.Threading;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

using Google.Apis.Auth.OAuth2;
using Google.Apis.Services;
using Google.Apis.Bigquery.v2;
using Google.Apis.Bigquery.v2.Data;

namespace BigQueryDemoApp
{
    public partial class _Default : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            UserCredential credential;
            FileStream stream;

            using (stream = new FileStream(
                    Server.MapPath("~/client_secrets.json"),
                    FileMode.Open, FileAccess.Read)
                )
            {
                GoogleWebAuthorizationBroker.Folder =
                    "Tasks.Auth.Store";
                credential = GoogleWebAuthorizationBroker.
                    AuthorizeAsync(
                    GoogleClientSecrets.Load(stream).Secrets,
                    new[] { BigqueryService.Scope.Bigquery },
                    "user", CancellationToken.None).Result;
            }

            // Initialize the service.
            var Service = new BigqueryService(
                new BaseClientService.Initializer()
                {
                    HttpClientInitializer = credential,
                    ApplicationName = "BigQueryDemo"
                }
            );
        }
    }
}

I set this specific page as the project start page. I picked "Installed application" when I built the Client ID file at the Google console

APIS & auth -> Credentials -> CREATE NEW CLIENT ID

and I made sure I added this file (client_secrets.json) with the solution explorer in VS2013. In the code-behind, I made sure that I correctly mapped to the client_secrets file with Server.MapPath. For the credential machinery, I used this code

<https://code.google.com/p/google-api-dotnet-client/wiki/OAuth2>

as the starting point. When I run the app, it returns a browser error page that starts with

Could not load file or assembly 'Microsoft.Threading.Tasks.Extensions.Desktop, Version=1.0.16.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.

and crashes at the "credential =" line. I tried to add in some images of the actual ASP.net crashed browser page showing the Assembly Load Trace / Stack Trace / etc. but it looks like I don't have the account rights for this. When I set a breakpoint at the "credential =" line and then run the app through

DEBUG -> Start Debugging

in VS2013, the page stops at the "credential =" line and a file picker opens, looking for file

"GoogleClientSecrets.cs"

from directory

"c:\code\google.com\google-api-dotnet-client\default\Tools\Google.Apis.Release\bin\Debug\output\default\Src\GoogleApis.Auth\OAuth2\GoogleClientSecrets.cs"

which is nowhere on the drive. Using the Assembly Load Trace in the generated ASP.net error page, I tried digging around through the suggested configuration files but nothing worked. More generally, I tried looking for this issue in StackOverflow and while I did find some mention of it, none of that material helped.

Answer 1

I already encountered this error before. It looks like the Bcl.Async package contains a reference to Microsoft.Threading.Tasks.Extensions.Desktop when you run a .NET 4.0 applications but somehow it is missing in .NET 4.5 application.

My advice for you (until I'll figure our with the owner of Microsoft.Bcl.Async why it happens) is to copy Microsoft.Threading.Tasks.Extensions.Desktop from packages\Microsoft.Bcl.Async.1.0.165\lib\net40\Microsoft.Threading.Tasks.Extensions.Desktop.dll to your BIN folder. It should solve this issue.

UPDATE (March 17th): Consider adding the following Post-build event to your project:

copy /Y "$(SolutionDir)packages\Microsoft.Bcl.Async.1.0.16\lib\net40\Microsoft.Threading.Tasks.Extensions.Desktop.dll" "$(TargetDir)Microsoft.Threading.Tasks.Extensions.Desktop.dll"

Unfortunately, there isn't a solution for this problem yet from the owners of the Bcl.Async package.

Answer 2

They released a new version of -Package Microsoft.Bcl.Async.

If somebody has this issue, please install the "latest" version instead of 1.0.16.

I hope it works for you.