The Entity Framework 4.2 Beta 1 is now available for download and comes with a small update to the DbContext & Code First runtime.
"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."
Microsoft's ADO.NET team blog explains that "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'," notes the ADO.NET team.