MVUX source generation fails in new Uno project: no generated files and broken bindings

[Georgios1999]

Current behavior 🐛

MVUX source generators do not run. No .g.cs output exists. Bindings fail with runtime errors like:

Error: BindingExpression path error: 'Value' property not found on
'Uno.Extensions.Reactive.Core.StateImpl`1[System.String]'.
BindingExpression: Path='ExampleText.Value'
DataItem='BindingBugRepro.Models.AppModel'
target element is 'Microsoft.UI.Xaml.Controls.Button'
target property is 'Content'

Expected behavior 🎯

• MVUX source generation should run
• .g.cs files should appear under obj/Debug/net8.0-windows10xx/generated
• MVUX state/feeds should generate bindable properties (e.g., .Value)
• Bindings should resolve correctly (e.g., {Binding ExampleText} → "Example")

How to reproduce it (as minimally and precisely as possible) 🔬

I made a minimal reproduction/testing repository here

Workaround 🛠️

No workaround. I have tried everything—from rebuilding to adding packages to finding a different way.

Renderer 🎨

• [x] Skia
• [ ] Native

Affected platforms 📱💻🖥️

Desktop (Windows), Windows App SDK, Desktop (X11), Build tasks

Uno.Sdk version (and other relevant versions) 📦

Uno SDK 6.4.26

IDE version 🧑‍💻

Visual Studio 2026 | Version: Insiders [11222.16]

Anything else we need to know? 💬

Detailed Observations

1. Missing properties in binding (runtime)

BindingExpression path error: 'Name' property not found
on 'Uno.Extensions.Reactive.Core.StateImpl`1[Workflow.Presentation.ViewModels.AppUser]'.
BindingExpression: Path='User.Name'
DataItem='Workflow.Presentation.ViewModels.UserViewModel'

2. MVUX Source Generator failure

FeedsGenerator fails due to duplicate hint names:

CSC : warning CS8785: Generator 'FeedsGenerator' failed to generate source.
It will not contribute to the output and compilation errors may occur as a result.
Exception was of type 'ArgumentException' with message:
'The hintName 'Workflow.Presentation.ViewModels.UserState.g.cs'
of the added source file must be unique within a generator.'

This appears to prevent all MVUX .g.cs files from being produced.

3. CPM (Central Package Management) errors

Wizard-generated project includes MVUX packages implicitly, but CPM rejects them:

The following PackageReference items cannot define a value for Version:
Uno.Extensions.Reactive.WinUI, Uno.Extensions.Reactive,
Uno.Extensions.Serialization.Json, Uno.Extensions.Reactive.Bindings.WinUI.
Projects using Central Package Management must define a Version value
on a PackageVersion item.

4. Missing or mismatched MVUX packages

On Windows Desktop target:

Unable to find package Uno.Extensions.Serialization.Json.
Unable to find package Uno.Extensions.Reactive.Bindings.WinUI.
Unable to find package Uno.Extensions.Reactive.UI with version (>= 7.0.4)

Detected package downgrade:
Uno.Extensions.Reactive from 7.0.4 to 5.2.6.

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This is reproducible just by selecting MVUX in the Setup Wizard, so just the defaults.