EF 4.2 Beta 1 Available


The information in this post is out of date.

Visit msdn.com/data/ef for the latest information on current and past releases of EF.


We recently posted about our plans to rationalize how we name, distribute and talk about releases.  We heard a resounding ‘Yes’ from you so then we posted about our plans for releasing EF 4.2. Today we are making EF 4.2 Beta 1 available.


EF 4.2 = Bug Fix + Semantic Versioning

When we released ‘EF 4.1 Update 1’ we introduced a bug that affects third party EF providers using a generic class for their provider factory implementation, things such as WrappingProviderFactory<TProvider>. We missed this during our testing and it was reported by some of our provider writers after we had shipped. If you hit this bug you will get a FileLoadException stating “The given assembly name or codebase was invalid”. This bug is blocking some third party providers from working with ‘EF 4.1 Update 1’ and the only workaround for folks using an affected provider is to ask them to remain on EF 4.1. So, we will be shipping this version to fix it, this will be the only change between ‘EF 4.1 Update 1’ and ‘EF 4.2’. Obviously a single bug fix wouldn’t normally warrant bumping the minor version, but we also wanted to take the opportunity to get onto the semantic versioning path rather than calling the release ‘EF 4.1 Update 2’.


Getting EF 4.2 Beta 1

The Beta is available via NuGet as the EntityFramework.Preview package.

If you already have the EntityFramework package installed then installing the Beta will overwrite the existing reference in your project. If you used the standalone installer for ‘EF 4.1’ or ‘EF 4.1 Update 1’ there is no need to uninstall.


Templates for Model First & Database First

The templates for using DbContext with Database First or Model First are now available on Visual Studio Gallery, rather than in a standalone installer.

Note: The templates for C# and VB.NET applications (including ASP.Net Web Applications, MVC, etc.) are available. The templates for ‘Web Sites’ will be available soon.

Right Click on the designer surface and select ‘Add Code Generation Item…’:


Select ‘Online Templates’ from the left menu and search for DbContext:




This is a preview of a future release and is designed to allow you to provide feedback. It is not intended or licensed for use in production. If you need assistance we have an Entity Framework Pre-Release Forum.


What’s Not in This Release?

As covered earlier this release is just a small update to the DbContext & Code First runtime. The features that were included in EF June 2011 CTP are part of the core Entity Framework runtime and will ship at a later date. Our Code First Migrations work is continuing and we are working to get the next alpha in your hands soon.


ADO.NET Entity Framework Team