stride3d/stride · error · InvalidOperationException

Unable to find the graph corresponding to the base part

Error message

Unable to find the graph corresponding to the base part

What it means

In AssetCompositeHierarchyPropertyGraph's base-asset change handler, this InvalidOperationException is thrown when Container.TryGetGraph(baseAsset.Id) does not return an AssetCompositeHierarchyPropertyGraph<TAssetPartDesign,TAssetPart>. A part changed in the base asset, but its graph is missing or not a hierarchy graph, so instance parts cannot be propagated. It enforces the invariant that a hierarchy base asset always has a matching hierarchy graph in the container.

Solutions

Load/restore the base composite asset so its hierarchy graph is registered in the container
Re-save or recreate the derived asset with a valid base reference
Rebuild the asset database/package to re-register missing graphs
Remove the base linkage from the derived asset if inheritance is no longer wanted

Example fix

// before
var graph = container.TryGetGraph(baseAssetId); // may be null / wrong type
// after
var graph = container.TryGetGraph(baseAssetId);
if (graph is null) { Console.Error.WriteLine($"Base asset {baseAssetId} not loaded; skipping propagation"); return; }

Defensive patterns

Strategy: try-catch

Validate before calling

var graph = Container.TryGetGraph(baseAsset.Id);
bool canPropagate = graph is AssetCompositeHierarchyPropertyGraph<TAssetPartDesign, TAssetPart>;

Type guard

if (Container.TryGetGraph(baseAsset.Id) is AssetCompositeHierarchyPropertyGraph<TAssetPartDesign, TAssetPart> baseGraph) { /* safe to propagate */ }

Try / catch

try { HandleBaseChanged(e); } catch (InvalidOperationException ex) when (ex.Message.Contains("graph corresponding to the base part")) { // reload base asset or remove derived asset's base link }

Prevention

Keep base composite assets loaded in the same container as derived assets
Do not change an asset's type after other assets derive from it
Rebuild the asset database after manual asset-file edits

When it happens

Trigger: Receiving a BaseAssetChanged event whose base asset Id has no graph registered in the container, or whose graph is a different graph type (e.g. a plain AssetPropertyGraph rather than a hierarchy graph).

Common situations: Base composite assets (prefab/scene-like assets) deleted or unloaded while derived assets remain; type mismatches after changing an asset's type; partial package loads; corrupted or hand-edited asset files with stale base references.

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/6598030344d023f8. Report an issue: GitHub.

Appendix: source

Thrown at sources/assets/Stride.Core.Assets.Quantum/AssetCompositeHierarchyPropertyGraph.cs:681

            }
        }

        // Register to new base part events
        foreach (var basePartAsset in newBasePartAsset)
        {
            basePartAsset.PartAdded += PartAddedInBaseAsset;
            basePartAsset.PartRemoved += PartRemovedInBaseAsset;
        }
    }

    private void PartAddedInBaseAsset(object? sender, AssetPartChangeEventArgs e)
    {
        UpdatingPropertyFromBase = true;

        var baseAsset = (AssetCompositeHierarchy<TAssetPartDesign, TAssetPart>)e.Asset;
        var newPart = baseAsset.Hierarchy.Parts[e.PartId];
        var newPartParent = baseAsset.GetParent(newPart.Part);
        if (Container.TryGetGraph(baseAsset.Id) is not AssetCompositeHierarchyPropertyGraph<TAssetPartDesign, TAssetPart> baseAssetGraph) throw new InvalidOperationException("Unable to find the graph corresponding to the base part");

        foreach (var instanceId in basePartAssets[baseAssetGraph])
        {
            // Discard the part if this asset don't want it
            if (!ShouldAddNewPartFromBase(baseAssetGraph, newPart, newPartParent, instanceId))
                continue;

            var insertIndex = FindBestInsertIndex(baseAsset, newPart, newPartParent, instanceId, out var instanceParent);
            if (insertIndex < 0)
                continue;

            // Now we know where to insert, let's clone the new part.
            const SubHierarchyCloneFlags flags = SubHierarchyCloneFlags.GenerateNewIdsForIdentifiableObjects | SubHierarchyCloneFlags.RemoveOverrides;
            var baseHierarchy = CloneSubHierarchies(baseAssetGraph.Container.NodeContainer, baseAssetGraph.Asset, newPart.Part.Id.Yield(), flags, out Dictionary<Guid, Guid> mapping);
            foreach (var ids in mapping)
            {
                // Process only ids that correspond to parts
                if (!baseHierarchy.Parts.TryGetValue(ids.Value, out var clone))

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