diff --git a/PROMS/Volian.Controls.Library/StepTabRibbon.cs b/PROMS/Volian.Controls.Library/StepTabRibbon.cs
index 57e76afc..bd272db8 100644
--- a/PROMS/Volian.Controls.Library/StepTabRibbon.cs
+++ b/PROMS/Volian.Controls.Library/StepTabRibbon.cs
@@ -1355,7 +1355,7 @@ namespace Volian.Controls.Library
 			StepData sd = MyItemInfo.FormatStepData;
 			actable = sd.StepEditData.AcTable;
 			if (actable == null) actable = 0;
-			btnInsHLS.Enabled = !MyItemInfo.IsEnhancedStep && !MyItemInfo.MyHLS.IsEnhancedStep; // (actable & E_AccStep.EnhancedLinkedStep) == 0;
+			btnInsHLS.Enabled = !MyItemInfo.IsEnhancedStep && MyItemInfo.MyHLS != null && !MyItemInfo.MyHLS.IsEnhancedStep; // (actable & E_AccStep.EnhancedLinkedStep) == 0;
 
 			btnInsCaut.Enabled = ((actable & E_AccStep.AddingCaution) > 0) && !MyItemInfo.IsEnhancedStep; // ((actable & E_AccStep.AddingCaution) > 0) && ((actable & E_AccStep.EnhancedLinkedStep) == 0);
 			btnInsNote.Enabled = ((actable & E_AccStep.AddingNote) > 0) && !MyItemInfo.IsEnhancedStep;