net 6 preview 3 web app 404 can not find routes

[ByronAP]

Describe the bug

Asp .net web application in 6 preview 3 can not find routes returns 404. It looks like this may be related to dotnet/razor#7577

To Reproduce

Create a new web application in visual studio, select framework 6.
Run the app and you will be greeted with a 404.

Exceptions (if any)

No exceptions are logged

Further technical details

• ASP.NET Core version 6 preview 3

.NET SDK (reflecting any global.json):
Version: 6.0.100-preview.3.21202.5
Commit: aee38a6dd4

Runtime Environment:
OS Name: Windows
OS Version: 10.0.19042
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\6.0.100-preview.3.21202.5\

Host (useful for support):
Version: 6.0.0-preview.3.21201.4
Commit: 236cb21e3c

.NET SDKs installed:
5.0.202 [C:\Program Files\dotnet\sdk]
6.0.100-preview.3.21202.5 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.1.27 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.27 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.14 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.0-preview.3.21201.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.27 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.0-preview.3.21201.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.14 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.0-preview.3.21201.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
https://aka.ms/dotnet-download

• VS 16.9.4

[javiercn]

@ByronAP thanks for contacting us.

I'm not able to reproduce this issue with the latest nightly build. I did dotnet new webapp -o sampleapp and everything seems to be in working order. This either doesn't repro or was fixed between preview3 or preview4.

We suggest you try the nightly builds or wait until preview4 to check if you still have this issue. Alternatively it would help if you can provide us with exact details on how you created and ran the application for us to try and reproduce it again.

[ByronAP]

Created a repo here https://github.com/ByronAP/aspnetcore-31788

Load with VS 2019 run as debug WebApplication1

[pranavkm]

@ByronAP I tried your app in VS, and it appears to work just fine. Is it possible that the issue you're seeing is specific to your machine?

[ByronAP]

Closing since it seems to not be reproduceable, Will come back on it when/if I find out the cause.

[ByronAP]

found something

An instance of analyzer Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator cannot be created from C:\Program Files\dotnet\sdk\6.0.100-preview.4.21214.14\Sdks\Microsoft.NET.Sdk.Razor\source-generators\Microsoft.NET.Sdk.Razor.SourceGenerators.dll : Could not load file or assembly 'Microsoft.CodeAnalysis, Version=3.10.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified..

[pranavkm]

FYI @captainsafia