stride3d/stride · error · InvalidOperationException

Unable to sort the given items for the Content collection…

Error message

Unable to sort the given items for the Content collection of PackageViewModel

What it means

PackageViewModel's Content collection sorter ends with a fallback InvalidOperationException when it cannot classify the compared items: neither an AssetViewModel, a DirectoryViewModel, nor a DependencyCategoryViewModel pattern matched. This guards against unknown item types sneaking into Content.

Solutions

Only add supported item types (asset, directory, dependency category) to Content
Extend the sort comparer if a new node type is legitimately needed
Remove unsupported items from Content before sorting

Example fix

// before
content.Add(myCustomNode);
// after
// keep custom nodes in a separate collection, or extend the comparer to handle myCustomNode

Defensive patterns

Strategy: validation

Validate before calling

if (content.Any(i => !(i is AssetViewModel || i is DirectoryViewModel || i is DependencyCategoryViewModel))) throw new InvalidOperationException("Unsupported item in PackageViewModel.Content");

Type guard

bool IsSortableContentItem(object i) => i is AssetViewModel || i is DirectoryViewModel || i is DependencyCategoryViewModel;

Try / catch

try { SortContent(content); } catch (InvalidOperationException) { /* remove unsupported items */ }

Prevention

Only add asset/directory/dependency-category nodes to Content
Extend the comparer for new node types
Keep custom nodes in separate collections

When it happens

Trigger: Inserting an item into PackageViewModel.Content that is not an asset, directory, or the single dependency category, then triggering a sort of the collection.

Common situations: Plugins adding custom view model nodes to the Content collection without extending the comparer.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/92be3b7746ef982c. Report an issue: GitHub.

Appendix: source

Thrown at sources/editor/Stride.Core.Assets.Editor/ViewModel/PackageViewModel.cs:794

                if (yAssets != null)
                    return string.Compare(xAssets.Name, yAssets.Name, StringComparison.InvariantCultureIgnoreCase);
                return -1;
            }
            if (xProject != null)
            {
                if (yProject != null)
                {
                    return xProject.CompareTo(yProject);
                }
                return yAssets != null ? 1 : -1;
            }
            if (xDependencies != null)
            {
                if (yDependencies != null)
                    throw new InvalidOperationException("A PackageViewModel cannot contain two isntances of DependencyCategoryViewModel");
                return 1;
            }
            throw new InvalidOperationException("Unable to sort the given items for the Content collection of PackageViewModel");
        }
    }
    public abstract class PickablePackageViewModel : DispatcherViewModel
    {
        protected PickablePackageViewModel([NotNull] IViewModelServiceProvider serviceProvider)
            : base(serviceProvider)
        {
        }

        public abstract string Name { get; }

        public abstract DependencyRange DependencyRange { get; }
    }

    public class LoadedPickablePackageViewModel : PickablePackageViewModel
    {
        public LoadedPickablePackageViewModel(PackageViewModel package) : base(package.ServiceProvider)
        {

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