diff -r f8c66edffbd4 -r 5f685bcd3ad6 dialogs/FBDVariableDialog.py
--- a/dialogs/FBDVariableDialog.py	Thu Apr 11 08:40:17 2019 +0200
+++ b/dialogs/FBDVariableDialog.py	Thu Apr 11 11:26:47 2019 +0200
@@ -195,7 +195,7 @@
                 self.ExecutionOrder.SetValue(value)
 
         # Refresh preview panel
-        self.DrawPreview()
+        self.Refresh()
         self.Fit()
 
     def GetValues(self):
@@ -242,7 +242,7 @@
         # Refresh name list box values
         self.RefreshNameList()
 
-        self.DrawPreview()
+        self.Refresh()
         event.Skip()
 
     def OnNameChanged(self, event):
@@ -255,7 +255,7 @@
         if self.VariableName.GetSelection() != wx.NOT_FOUND:
             self.Expression.ChangeValue(self.VariableName.GetStringSelection())
 
-        self.DrawPreview()
+        self.Refresh()
         event.Skip()
 
     def OnExpressionChanged(self, event):
@@ -267,7 +267,7 @@
         self.VariableName.SetSelection(
             self.VariableName.FindString(self.Expression.GetValue()))
 
-        self.DrawPreview()
+        self.Refresh()
         event.Skip()
 
     def OnExecutionOrderChanged(self, event):
@@ -275,7 +275,7 @@
         Called when block execution control value changed
         @param event: wx.SpinEvent
         """
-        self.DrawPreview()
+        self.Refresh()
         event.Skip()
 
     def DrawPreview(self):