diff --git a/RhSolutions.AddIn/Services/ExcelWriter.cs b/RhSolutions.AddIn/Services/ExcelWriter.cs
index 4ac4f2b..ab04c50 100644
--- a/RhSolutions.AddIn/Services/ExcelWriter.cs
+++ b/RhSolutions.AddIn/Services/ExcelWriter.cs
@@ -182,7 +182,7 @@ public class ExcelWriter : IWriter, IDisposable
         previous.Copy(current);
         current.ClearContents();
 
-        worksheetCells[row, groupColumn].Value2 = positionAmount.Key.ProductLines.First();
+        worksheetCells[row, groupColumn].Value2 = positionAmount.Key.ProductLines.FirstOrDefault() ?? string.Empty;
         worksheetCells[row, nameColumn].Value2 = positionAmount.Key.Name;
 
         if (_oldSkuCell != null)