.NET 8 preview7 Blazor WASM AAD authentication ends with There was an error trying to log you in: '"undefined" is not valid JSON'

[haslingerm]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

I am getting the same issue as described in #44981 again: after coming back from login at Azure AD the user sees 'There was an error trying to log you in: '"undefined" is not valid JSON'' at the 'authentication/login-failed' route.

However, after manually navigating around the token is available so it kind-of worked anyway.

Same as with the previous issue, adding the following solves the issue, so I suspect a similar cause:

<ItemGroup>
    <TrimmerRootAssembly Include="Microsoft.AspNetCore.Components.WebAssembly.Authentication" />
</ItemGroup>

Also: error does not appear during development, only after publish also pointing to the linker

Expected Behavior

No error should be displayed after the redirect if the operation was successful.

Steps To Reproduce

Standard Blazor WASM application using Microsoft.Authentication.WebAssembly.Msal (8.0.0-preview.7.23375.9), set up to use 'redirect' and not the 'pop up' auth option.

Exceptions (if any)

No response

.NET Version

8.0.100-preview.7.23376.3

Anything else?

No response

Thanks for contacting us.

We're moving this issue to the .NET 9 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
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[hectorm-bmg]

I'm getting a similar behavior ("undefined" is not valid JSON') but in this case I'm using Azure ADB2C with an IdentityServer4 external provider.
I tried using

<ItemGroup> <TrimmerRootAssembly Include="Microsoft.Authentication.WebAssembly.Msal" /> </ItemGroup>

but the issue is still there. Any suggestions would be appreciated.

[mkArtakMSFT]

@halter73 isn't this something you've addressed already (your PR to the some AAD library I think) ?