Is TPL DataFlow included with either .NET 4.5 or .NET 4.5.1?

Question

I'm confused. We upgraded our project recently to .NET 4.5.1. We installed .NET 4.5.1 on our servers.

I'm referencing assembly System.Threading.Tasks.Dataflow from the GAC at C:\windows\Microsoft.Net\assembly\GAC_MSIL\System.Threading.Tasks.Dataflow\v4.0_4.5.9.0__b03f5f7f11d50a3a\System.Threading.Tasks.Dataflow.dll

CopyLocal is set to false as (I assume) it's part of the Framework, so should be already installed wherever the app is deployed.

The trouble is, when running on the server, it says it can't find this assembly.

I've read here that is is part of .NET Framework 4.5:

but the library is now built-in with .NET 4.5.

...and I've read here that it isn't!

The TPL Dataflow Library (System.Threading.Tasks.Dataflow namespace) is not distributed with the .NET Framework 4.5

What gives? It doesn't look like it is. Is it just part of the 'targetting pack'? Is it me, or are these in-place upgrades more agro than they're worth?!

Answer 1

I'm not sure why that page says it is part of .NET 4.5 -- it's still an out-of-band NuGet release, like Entity Framework, MVC, etc.

Answer 2

I recognize this question is pretty old, but I wanted to add my solution as well. I found adding the below two items to the Visual Studio 2019 install (run Visual Studio Installer > Modify > .Net Desktop Development) the problem went away and it was able to pull System.Threading.Tasks.Dataflow from the GAC.

Edit: Installing Visual Studio 2015 also seemed to be required. Obviously it isn't VS 2015 itself, just something it comes with. But there are too many packages for me to figure out which one easily.

Edit2: This isn't really the best solution, more of a stopgap. MS suggests downloading it through Nuget. https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.dataflow?view=netcore-3.1

The TPL Dataflow Library (the System.Threading.Tasks.Dataflow namespace) is not distributed with .NET. To install the System.Threading.Tasks.Dataflow namespace in Visual Studio, open your project, choose Manage NuGet Packages from the Project menu...