stride3d/stride · error · NotSupportedException

Can't change the name of a UIPage object.

Error message

Can't change the name of a UIPage object.

What it means

The Name setter of UIPageRootViewModel always throws NotSupportedException: the root of a UI page asset is a fixed pseudo-node labeled 'UI Page' whose display name cannot be changed through the view model.

Solutions

  1. Rename the UIPage asset itself rather than the root view model's Name.
  2. Treat the page root's Name as read-only in the UI (disable rename for the root node).
  3. Exclude root nodes from rename operations.

Example fix

// before
pageRootViewModel.Name = "MyPage";
// after
pageRootViewModel.Asset.Asset.Name = "MyPage"; // rename the asset, not the root node
Defensive patterns

Strategy: type-guard

Validate before calling

bool canRename = !(node is UIPageRootViewModel);

Type guard

static bool IsRenamable(IAssetNodeViewModel node) => !(node is UIPageRootViewModel);

Try / catch

try { node.Name = newName; } catch (NotSupportedException ex) { /* rename the asset instead */ }

Prevention

When it happens

Trigger: Assigning to Name on the UIPage root view model, e.g. a TwoWay name binding in a property grid or calling the tree rename command on the page root.

Common situations: Generic rename UI applied to all hierarchy nodes; scripted bulk renaming that includes root nodes; expecting the root's Name to mirror the asset name.

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/a4b4f4aa514d6a39. Report an issue: GitHub.

Appendix: source

Thrown at sources/editor/Stride.Assets.Presentation/AssetEditors/UIPageEditor/ViewModels/UIPageRootViewModel.cs:33

namespace Stride.Assets.Presentation.AssetEditors.UIPageEditor.ViewModels
{
    public sealed class UIPageRootViewModel : UIRootViewModel, IAddChildViewModel
    {
        /// <summary>
        /// A UIPage asset cannot have more than one root.
        /// </summary>
        internal static readonly string OneRootOnly = "A UIPage asset can't have more than one root.";

        public UIPageRootViewModel([NotNull] UIEditorBaseViewModel editor, [NotNull] UIPageViewModel asset, UIElementDesign rootElement)
            : base(editor, asset, rootElement?.Yield())
        {
            NotifyGameSidePartAdded().Forget();
        }

        /// <inheritdoc />
        [NotNull]
        public override string Name { get => "UI Page"; set => throw new NotSupportedException("Can't change the name of a UIPage object."); }

        [CanBeNull]
        public UIElementViewModel RootElement => RootElements.SingleOrDefault();

        /// <inheritdoc />
        public override void ReplaceRootElement(PanelViewModel sourcePanel, AssetCompositeHierarchyData<UIElementDesign, UIElement> hierarchy, Guid targetPanelId)
        {
            if (sourcePanel == null) throw new ArgumentNullException(nameof(sourcePanel));
            if (sourcePanel.Id.ObjectId != Asset.Asset.Hierarchy.RootParts.Single().Id)
                throw new ArgumentException(@"The given source panel does not match the currently set root element", nameof(sourcePanel));

            Asset.AssetHierarchyPropertyGraph.RemovePartFromAsset(sourcePanel.UIElementDesign);
            Asset.AssetHierarchyPropertyGraph.AddPartToAsset(hierarchy.Parts, hierarchy.Parts[targetPanelId], null, Asset.Asset.Hierarchy.RootParts.Count);
        }

        /// <inheritdoc />
        // ReSharper disable once RedundantAssignment
        protected override bool CanAddOrInsertChildren(IReadOnlyCollection<object> children, ref string message)

View on GitHub (pinned to 96fad776d2)