Fixed crash in PopupList Filters

inabox.wpf/DynamicGrid/DynamicGrid.cs

@@ -2578,9 +2578,14 @@ namespace InABox.DynamicGrid
         {
             if (string.IsNullOrWhiteSpace(value))
                 return;
+            var col = DataGrid.Columns.FirstOrDefault((x=>String.Equals(x.MappingName?.ToUpper(),column?.Replace(".", "_").ToUpper())));
+            if (col != null)
+            {
+                col.FilterPredicates.Add(new FilterPredicate { FilterType = filtertype, FilterValue = value });
+                col.FilteredFrom = FilteredFrom.FilterRow;
+
+            }
 
-            DataGrid.Columns[column].FilterPredicates.Add(new FilterPredicate { FilterType = filtertype, FilterValue = value });
-            DataGrid.Columns[column].FilteredFrom = FilteredFrom.FilterRow;
         }
 
         #endregion