diff --git a/src/components/MatrixView.tsx b/src/components/MatrixView.tsx
index 3c34672..03a6094 100644
--- a/src/components/MatrixView.tsx
+++ b/src/components/MatrixView.tsx
@@ -121,8 +121,7 @@ export function MatrixView({ data, headers, rowStatuses }: MatrixViewProps) {
   const formatCellValue = (val: any, header: string = '') => {
     if (val === undefined || val === null || val === '') return '';
 
-    // Convert header to lowercase for checks
-    const h = header.toLowerCase();
+    const h = (header || '').toLowerCase();
 
     // Handle date columns - Excel serial dates are numbers >= 25569 (Jan 1, 1970)
     if (h.includes('date') || h.includes('launch') || h.includes('ready')) {
diff --git a/src/components/MissingDataView.tsx b/src/components/MissingDataView.tsx
index 828df7d..1997e3d 100644
--- a/src/components/MissingDataView.tsx
+++ b/src/components/MissingDataView.tsx
@@ -80,14 +80,14 @@ export function MissingDataView({ data, headers, onSaveRow, onCaptureState }: Mi
   const pageSize = 100;
 
   const launchDateCol = useMemo(() => {
-    const idx = headers.findIndex(h => h.toLowerCase().includes('launch'));
+    const idx = headers.findIndex(h => (h || '').toLowerCase().includes('launch'));
     if (idx >= 0) return idx;
-    return headers.findIndex(h => h.toLowerCase().includes('date'));
+    return headers.findIndex(h => (h || '').toLowerCase().includes('date'));
   }, [headers]);
   const readyToOrderCol = useMemo(() => {
-    const idx = headers.findIndex(h => h.toLowerCase().includes('ready'));
+    const idx = headers.findIndex(h => (h || '').toLowerCase().includes('ready'));
     if (idx >= 0) return idx;
-    return headers.findIndex(h => h.toLowerCase().includes('order'));
+    return headers.findIndex(h => (h || '').toLowerCase().includes('order'));
   }, [headers]);
 
   const launchHeader = launchDateCol >= 0 ? headers[launchDateCol] : 'Launch Date';