diff --git a/packages/api/src/localizedTree.ts b/packages/api/src/localizedTree.ts
index 50f950d..3c1b9bf 100644
--- a/packages/api/src/localizedTree.ts
+++ b/packages/api/src/localizedTree.ts
@@ -39,6 +39,15 @@ export class TypeInfoLocalizer {
 
     constructor(private retrieveTypeInfo?: TypeInfoRetriever) {}
 
+    hasTypeInfo(info: TypeInfo): boolean {
+        return this.typeInfoMaps.has(info)
+    }
+
+    hasLocalizedTypeInfo(localizedInfo: LocalizedTypeInfo): boolean {
+        const info = this.localizedInfoOrigin.get(localizedInfo)
+        return !!(info && this.hasTypeInfo(info))
+    }
+
     private localizeTypeInfo(
         resolvedInfo: ResolvedArrayTypeInfo,
         info?: TypeInfo,
diff --git a/packages/typescript-explorer-vscode/src/view/typeTreeView.ts b/packages/typescript-explorer-vscode/src/view/typeTreeView.ts
index 67430ba..7c4a668 100644
--- a/packages/typescript-explorer-vscode/src/view/typeTreeView.ts
+++ b/packages/typescript-explorer-vscode/src/view/typeTreeView.ts
@@ -102,7 +102,11 @@ export class TypeTreeProvider implements vscode.TreeDataProvider<TypeTreeItem> {
                 this.createTypeNode(localizedTypeInfo, /* root */ undefined),
             ]
         } else {
-            assert(this.typeInfoLocalizer, "typeInfoLocalizer should exist")
+            if (
+                !this.typeInfoLocalizer?.hasLocalizedTypeInfo(element.typeInfo)
+            ) {
+                return []
+            }
 
             const localizedChildren =
                 await this.typeInfoLocalizer.localizeChildren(element.typeInfo)