stride3d/stride · error · InvalidOperationException

The path [ ] contains a non-valid item id on an dictionary.

Error message

The path [{ToString()}] contains a non-valid item id on an dictionary.

What it means

Thrown by YamlAssetPath.ToMemberPath when an ItemId path element resolves against a dictionary but the derived key is null. A null key cannot address any dictionary entry, so the library rejects the path rather than producing an invalid MemberPath node.

Solutions

1. Update the asset YAML to reference an existing dictionary key
2. Re-add the missing dictionary entry or migrate stored ids after refactoring key types
3. Regenerate the reference in the editor so the id map and path stay in sync
4. Catch InvalidOperationException around ToMemberPath and treat it as a stale reference to repair

Example fix

// before (yaml references an id missing from the dictionary)
myDict: !AssetRef itemId="missing"
// after
myDict: !AssetRef key="existingKey"

var key = ids.GetKey(itemId); if (key is null) throw new ArgumentException("Dictionary item id does not resolve to a key");

bool HasValidDictKey(CollectionItemIds ids, ItemId id) => ids.GetKey(id) != null;

try { memberPath = yamlPath.ToMemberPath(); } catch (InvalidOperationException) { MarkReferenceBroken(asset, yamlPath); }

When it happens

Trigger: In the ElementType.ItemId branch, currentObject's descriptor is a DictionaryDescriptor and the key obtained from CollectionItemIdHelper.GetCollectionItemIds(currentObject).GetKey(item.AsItemId()) is null.

Common situations: Stored item id no longer present in the dictionary's id map (entry deleted or renamed); asset YAML serialized by an older/other tool version; hand-edited paths pointing at removed dictionary entries.

Understand the failure class

Background: "Not found" and "does not exist" errors: why "Task not found", "No such folder", and "Can't find" fire when a lookup comes back empty — this error's family across 14 libraries.

Related errors

• The path [ ] contains a null key on an dictionary.
• The path [ ] contains a non-valid item id on an array.
• The path [ ] contains a non-valid item id on a collection.
• Non-scalar key not yet supported!
• The path [ ] contains non-integer index on an array.

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/23bc88623cd5415c. Report an issue: GitHub.

Appendix: source

Thrown at sources/assets/Stride.Core.Assets/Yaml/YamlAssetPath.cs:321

                            {
                                if (item.Value is null && !collectionDescriptor.ElementType.IsNullable())
                                {
                                    throw new InvalidOperationException($"The path [{ToString()}] contains a null item on a set.");
                                }
                            }
                            else
                            {
                                if (key is not int)
                                {
                                    throw new InvalidOperationException($"The path [{ToString()}] contains a non-valid item id on a collection.");
                                }
                            }
                            memberPath.Push(collectionDescriptor, key);
                            currentObject = collectionDescriptor.GetValue(currentObject, key);
                        }
                        else if (typeDescriptor is DictionaryDescriptor dictionaryDescriptor)
                        {
                            if (key is null) throw new InvalidOperationException($"The path [{ToString()}] contains a non-valid item id on an dictionary.");
                            memberPath.Push(dictionaryDescriptor, key);
                            currentObject = dictionaryDescriptor.GetValue(currentObject, key);
                        }
                        break;
                    }
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }

        return memberPath;
    }

    /// <summary>
    /// Creates a <see cref="YamlAssetPath"/> out of a <see cref="MemberPath"/> instance.
    /// </summary>
    /// <param name="path">The <see cref="MemberPath"/> from which to create a <see cref="YamlAssetPath"/>.</param>
    /// <param name="root">The root object of the given <see cref="MemberPath"/>.</param>

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