From 6358535301fe2e003ceac9596ff44819bd969c0e Mon Sep 17 00:00:00 2001
From: Patrik Kozak <patrik@payloadcms.com>
Date: Fri, 21 Feb 2025 14:56:04 -0500
Subject: [PATCH] fix: fallback to doc ID if useAsTitle field is undefined

---
 packages/plugin-nested-docs/src/utilities/formatBreadcrumb.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/plugin-nested-docs/src/utilities/formatBreadcrumb.ts b/packages/plugin-nested-docs/src/utilities/formatBreadcrumb.ts
index b7ee116e9f8..bde6c70dd92 100644
--- a/packages/plugin-nested-docs/src/utilities/formatBreadcrumb.ts
+++ b/packages/plugin-nested-docs/src/utilities/formatBreadcrumb.ts
@@ -20,7 +20,9 @@ export const formatBreadcrumb = (
     label = pluginConfig.generateLabel(docs, lastDoc)
   } else {
     const useAsTitle = collection?.admin?.useAsTitle || 'id'
-    label = lastDoc[useAsTitle] as string
+
+    // Fallback to ID if useAsTitle field is not filled (e.g., optional fields).
+    label = (lastDoc[useAsTitle] ?? lastDoc.id) as string
   }
 
   return {