Added a null reference check for selectedDVI on the tc_PanelTabDisplay() function.

Added logic to skip the checks for changed integrated graphics (figures) when the RO database has none.

PROMS/VEPROMS User Interface/frmVEPROMS.cs

@@ -2889,6 +2889,7 @@ namespace VEPROMS
 		}
 		private void tc_PanelTabDisplay(object sender, StepPanelTabDisplayEventArgs args)
 		{
+			if (_SelectedDVI == null) return;
 			if (args.PanelTabName == "Bookmarks")
 			{
 				toolsPanel.Expanded = true;