Fix error with missing columns in CTRL placeholder

app/DD_PM_WINDREAM/clsPatterns.vb

@@ -197,6 +197,8 @@ Public Class clsPatterns
                     oColumnName = oSplitName.Last()
                 End If
 
+                LOGGER.Debug("Found placeholder for control [{0}].", oControlName)
+
                 Dim oControl As Control = oPanel.Controls.Find(oControlName, False).FirstOrDefault()
 
                 If oControl IsNot Nothing Then
@@ -233,13 +235,13 @@ Public Class clsPatterns
                                 Where(Function(c) c.FieldName = oColumnName).
                                 SingleOrDefault()
 
-                            If oColumn Is Nothing Then
+                            If oColumn?.SummaryItem?.SummaryValue Is Nothing Then
                                 LOGGER.Warn("Column [{0}] not found in Grid!", oColumnName)
                                 oReplaceValue = ERROR_REPLACE_VALUE
+                            Else
+                                oReplaceValue = oColumn.SummaryItem.SummaryValue
                             End If
 
-                            oReplaceValue = oColumn.SummaryItem.SummaryValue
-
                         Case Else
                             oReplaceValue = ERROR_REPLACE_VALUE
                     End Select