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The type or namespace name 'Mvc' does not exist in the namespace 'Microsoft.AspnetCore' (are you missing an assembly reference?)

See original GitHub issue

Describe the bug

in blazor project, When i update the .Net Core 3.0.0.Preview4 and then changes all the .cshtml in to .razor pages i have faced this issue “The type or namespace name ‘Mvc’ does not exist in the namespace ‘Microsoft.AspnetCore’ (are you missing an assembly reference?)”

Can one help me for how to resolve this?

Expected behavior

Need to be build succeed

Screenshots

bla4

Additional context

Add any other context about the problem here. Include the output of dotnet --info

Issue Analytics

State:
Created 4 years ago
Reactions:3
Comments:54 (14 by maintainers)

Top GitHub Comments

3reactions

vignatovcommented, May 1, 2019

Same situation here. 2 projects, 1 is building fine, another fails with this error. Both are client-side Blazor projects.

2reactions

chuckercommented, Aug 29, 2019

@Legends

Regarding VS Preview: note that you’re quoting a comment that refers to the then-new 16.1 Preview. Regardless, Blazor preview 7 and up does require VS 16.3 Preview to fully work, because it includes some Razor tooling changes:

Visual Studio users need Visual Studio 2019 16.3 Preview 1 to use .NET Core 3.0 Preview 7.

The “Preview Features” SDK checkbox isn’t quite the same thing. What it does is allow you to use a .NET Core 3.0 preview from a non-preview VS at all. It does not, however, include the complete tooling for Blazor.

Note that VS previews will install side-by-side with the regular VS, so while it will take some time to install and take up a fair amount of disk space, it won’t really interfere with your production stuff.

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