Reproduction steps:
1. Create a new project
2. Install App UI Package via Package Manager or AI button in the top Editor toolbar
3. Window > Package Management > Package Manager > App UI > Samples
4. Import UI Kit Sample and observe the Console
Actual result: “Assets/Samples/App UI/2.1.3/UI Kit/Scripts/Examples.cs(551,36): error CS0104: 'MaskField' is an ambiguous reference between 'Unity.AppUI.UI.MaskField' and 'UnityEngine.UIElements.MaskField'” error is thrown
Expected result: No warnings or errors are thrown
Reproducible with: 2.1.1 (6000.5.0a4), 2.1.3 (6000.5.0a1, 6000.5.0a4)
Not reproducible with: 2.1.3 (6000.0.65f1, 6000.3.3f1, 6000.4.0a3, 6000.4.0b3)
Reproduced on: macOS Tahoe 26.2 (M4)
Note: FAV is in the Editor version