ASP.NET Core and Blazor updates in .NET Core 3.0 Release Candidate 1

Daniel Roth

.NET Core 3.0 Release Candidate 1 (RC1) is now available. This release contains only a handful of bug fixes and closely represents what we expect to release for .NET Core 3.0.

Please see the release notes for additional details and known issues.

Get started

To get started with ASP.NET Core in .NET Core 3.0 RC1 install the .NET Core 3.0 RC1 SDK.

If you’re on Windows using Visual Studio, install the latest preview of Visual Studio 2019.

.NET Core 3.0 RC1 requires Visual Studio 2019 16.3 Preview 4 or later.

There is also a Blazor WebAssembly preview update available with this release. This update to Blazor WebAssembly still has a Preview 9 version, but carries an updated build number. This is not a release candidate for Blazor WebAssembly. Blazor WebAssembly isn’t expected to ship as a stable release until some time after .NET Core 3.0 ships (details coming soon!).

To install the latest Blazor WebAssembly template run the following command:

dotnet new -i Microsoft.AspNetCore.Blazor.Templates::3.0.0-preview9.19457.4

Upgrade an existing project

To upgrade an existing ASP.NET Core app to .NET Core 3.0 Preview 9, follow the migrations steps in the ASP.NET Core docs.

Please also see the full list of breaking changes in ASP.NET Core 3.0.

To upgrade an existing ASP.NET Core 3.0 Preview 9 project to RC1:

  • Update all Microsoft.AspNetCore.* package references to 3.0.0-rc1.19457.4
  • Update all Microsoft.AspNetCore.Blazor.* package references to 3.0.0-preview9.19457.4
  • Update all Microsoft.Extensions.* package references to 3.0.0-rc1.19456.10

That’s it You should now be all set to use .NET Core 3.0 RC1!

Give feedback

We hope you enjoy the new features in this preview release of ASP.NET Core and Blazor! Please let us know what you think by filing issues on GitHub.

Thanks for trying out ASP.NET Core and Blazor!


Discussion is closed. Login to edit/delete existing comments.

  • AlseinX 0

    Is there any information about EF Core 3.0 Preview or RC? It recently changes frequently. Will it come out at a stable version with .NET Core 3.0 GA?

  • Dean Jackson 0 is slow to load (for /VisualStudio and individual article pages) if you are logged in, and using Firefox Windows (latest release) or Edge 18 (44.18362.1.0). If I’m not logged in, it loads faster.

    • Radhika Tadinada Microsoft employee 0

      Hey Dean,

      I apologize for the ongoing slowness for signed in experiences. We are aware and working to improve this. We hope to improve signed in page load times soon.

  • manish sharma 0

    Can anyone suggest the release date of stable version of Blazor Client Side(Webassembly)?

  • Sebastian Redl 0

    You also need to update Microsoft.Extensions.* package references, and they have a different version number from the Microsoft.AspNetCore.* packages. Can you list the version for those too for the release announcements?

    • Daniel RothMicrosoft employee 0


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