Cannot debug the library in external projects

[MarvinKlein1508]

🐛 Bug Report

You can't simply debug the core library within external projects.

💻 Repro or Code Sample

1. Clone: https://github.com/MarvinKlein1508/FluentUI-Debug-Issue
2. Open in Visual Studio
3. Right click the solution and choose: Add->Existing Project...
4. Add the local copy of the Microsoft.FluentUI.AspNetCore.Components project
5. Add project reference to the added project
6. Start debug

🤔 Expected Behavior

I expect the app to boot up normally.

😯 Current Behavior

The app crashes because design themes cannot be initialized. When you comment out the design setup in App.razor and Route.razor the app will boot but all CSS and JS from the components are missing.

💁 Possible Solution

It would be great to have some kind of docs in the repository how we can setup debugging for external projects.

🔦 Context

I need to be able to debug some stuff in our main project which I can't simply copy over and provide to Github.

🌍 Your Environment

• Windows 11 Professional 64Bit
• Latest Firefox and Edge
• .NET and Fluent UI Blazor library Version 4.12.2

[vnbaaij]

I followed the exact steps you described (and as I explained them to you earlier). It works for me:

[MarvinKlein1508]

@vnbaaij can you record a small video for me? Perhaps I'm clicking something wrong?

[vnbaaij]

Here you go:

debug.Fluent.in.own.project.mp4

Moving this to the discussion area as it is not really an issue.

[MarvinKlein1508]

Interesting. It seems to make a difference on how you add the reference. You did it via drag and drop - I did it via right clicking on references and Add project reference. When I do it with drag and drop this works for me as well. Seems to be an issue with Visual Studio

[vnbaaij]

I recall using the right clicking in the past as well. Because the number of projects in the Aspire solution is huge and drag and drop was taking to long. That was on VS2022 and it worked for me back then as well. So maybe a VS2026 thing?

[dvoituron]

What is the difference included in the csproj when you use a Drag/Drop or a Add project reference actions?

[vnbaaij]

Good question!

[MarvinKlein1508]

@vnbaaij ok I take back what I said. This seems to be another issue. On ym PC at home it's working fine. But not on my work PC. I have recorded my steps in this short video.
https://www.youtube.com/watch?v=uHJWCqDlAZ0

Any idea what's happening here? Do I need something else installed on my machine to get it working? In Visual Studio I have this three installed:

And my programs:

[MarvinKlein1508]

I figured out what went wrong. See #4352