Fix to Memo columns

inabox.wpf/DynamicGrid/Columns/EditorColumns/DynamicGridMemoColumn.cs

@@ -16,8 +16,8 @@ public class DynamicGridMemoColumn : DynamicGridEditorColumn<MemoEditor, GridTex
         {
             Path = new PropertyPath(mapping), 
             Converter = new FuncConverter<object?, string>(
-                x => x is string[] strArr ? string.Join('\n', strArr) : "",
-                x => x.Split('\n'))
+                x => x is string[] strArr ? string.Join('\n', strArr) : (x?.ToString() ?? ""),
+                x => x)
         };
         column.DisplayBinding = binding;
         column.ValueBinding = binding;