Blazor WASM logout results in 404

[skanva]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

I have created a Blazor WASM app following the instructions from:
https://learn.microsoft.com/en-us/aspnet/core/blazor/security/webassembly/standalone-with-microsoft-entra-id?view=aspnetcore-9.0

I am using net9.0 and latest nuget packages.

For the configuration in wwwroot/appsettings.json I had to change the authority to this format:
"https://{TenantName}.ciamlogin.com/{TenantName}.onmicrosoft.com"
where {TenantName} is the name of my tenant.

When I run locally I can log in and log out successfully. But when I deploy this to Azure SWA, I can log in, but log out results in 404.

The browser url shows:
https://{my-swa-url}.azurestaticapps.net/authentication/logout-callback?state=52244933-59a1-4379-8dc0-e0f9a21db7ff

with page displaying:
404: Not Found
We couldn’t find that page, please check the URL and try again.

How can I resolve the log out issue so it successfully completes and returns user to site?

cc: @guardrex dotnet/AspNetCore.Docs#35421

Expected Behavior

Logout should complete successfully and redirect to home page

Steps To Reproduce

Follow this doc to create the project
https://learn.microsoft.com/en-us/aspnet/core/blazor/security/webassembly/standalone-with-microsoft-entra-id?view=aspnetcore-9.0

I am using net9.0 and latest nuget packages.

I am using a Microsoft Entra External ID tenant. So for the configuration in wwwroot/appsettings.json I had to change the authority to this format:
"https://{TenantName}.ciamlogin.com/{TenantName}.onmicrosoft.com"
where {TenantName} is the name of my tenant.

Exceptions (if any)

No response

.NET Version

9.0.203

Anything else?

No response

[MackinnonBuck]

Thanks for reaching out, @skanva.

Could you please show us your Authentication.razor file? It should be similar to the template code. Could you please confirm by looking at the browser developer tools which exact URL is returning the 404?

[skanva]

Hi @MackinnonBuck
The Authentication.razor is exactly as the template code you linked. There are no changes to any files except for wwwroot/appsettings.json where I needed to update the authority to point to the one for External ID tenant. Everything else is from following this article:
https://learn.microsoft.com/en-us/aspnet/core/blazor/security/webassembly/standalone-with-microsoft-entra-id?view=aspnetcore-9.0

From the browser dev tools, the url that is failing is:
https://{mydomain}.westus2.6.azurestaticapps.net/authentication/logout-callback?state=ef23c961-84fa-4dd1-ab8c-d4df2d153782

This has status code 404.

Note this only happens when the app is deployed to Azure SWA.

When running locally and I do a logout, I see this
https://localhost:7049/authentication/logout-callback?state=74865aa9-1884-469f-9e2f-3985dc25f5ee
Which has http status 200 and my app returns to home page as expected.

[MackinnonBuck]

@skanva, it looks like the issue might be specific to the app's Azure SWA configuration.

Could you please check out these docs for configuring the fallback route and see if they help resolve your issue?

[skanva]

@MackinnonBuck, adding the staticwebapp.config.json to the wwwroot folder fixed the issue. Should this be automatically added when the project is created? If not would be good to mention that as an additional step in the doc here:
https://learn.microsoft.com/en-us/aspnet/core/blazor/security/webassembly/standalone-with-microsoft-entra-id?view=aspnetcore-9.0
Seems like would be needed when deploying to support logout.
In any case this can be closed. Thanks!