Я изменил проект

Kovalev1App/MainWindow.xaml

@@ -5,16 +5,4 @@
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:Kovalev1App"
         mc:Ignorable="d"
-        Title="MainWindow" Height="450" Width="800">
-    <Grid Margin="-2,10,2,-10">
-        <Grid.RowDefinitions>
-            <RowDefinition Height="207*"/>
-            <RowDefinition Height="212*"/>
-        </Grid.RowDefinitions>
-        <Grid.ColumnDefinitions>
-            <ColumnDefinition Width="199*"/>
-            <ColumnDefinition Width="197*"/>
-        </Grid.ColumnDefinitions>
-
-    </Grid>
-</Window>
+        Title="MainWindow" Height="450" Width="800"/>