diff --git a/web/app/components/workflow/hooks/use-checklist.ts b/web/app/components/workflow/hooks/use-checklist.ts
index 8a29551b89..98531169df 100644
--- a/web/app/components/workflow/hooks/use-checklist.ts
+++ b/web/app/components/workflow/hooks/use-checklist.ts
@@ -116,7 +116,9 @@ export const useChecklist = (nodes: Node[], edges: Edge[]) => {
 
       if (node.type === CUSTOM_NODE) {
         const checkData = getCheckData(node.data)
-        let { errorMessage } = nodesExtraData![node.data.type].checkValid(checkData, t, moreDataForCheckValid)
+        // temp fix nodeMetaData is undefined
+        const nodeMetaData = nodesExtraData?.[node.data.type]
+        let { errorMessage } = nodeMetaData?.checkValid ? nodeMetaData.checkValid(checkData, t, moreDataForCheckValid) : { errorMessage: undefined }
 
         if (!errorMessage) {
           const availableVars = map[node.id].availableVars
diff --git a/web/app/components/workflow/nodes/iteration/node.tsx b/web/app/components/workflow/nodes/iteration/node.tsx
index 0232c8755f..fe265ae5ed 100644
--- a/web/app/components/workflow/nodes/iteration/node.tsx
+++ b/web/app/components/workflow/nodes/iteration/node.tsx
@@ -58,7 +58,7 @@ const Node: FC<NodeProps<IterationNodeType>> = ({
         )
       }
       {
-        data._children!.length === 1 && (
+        data._children?.length === 1 && (
           <AddBlock
             iterationNodeId={id}
             iterationNodeData={data}
diff --git a/web/app/components/workflow/nodes/loop/node.tsx b/web/app/components/workflow/nodes/loop/node.tsx
index 57be10be6e..b1e1befeed 100644
--- a/web/app/components/workflow/nodes/loop/node.tsx
+++ b/web/app/components/workflow/nodes/loop/node.tsx
@@ -46,7 +46,7 @@ const Node: FC<NodeProps<LoopNodeType>> = ({
         )
       }
       {
-        data._children!.length === 1 && (
+        data._children?.length === 1 && (
           <AddBlock
             loopNodeId={id}
             loopNodeData={data}