XamlParseException occurred:

The property ‘VerticalGridlinesBrush’ was not found in type ‘System.Windows.Controls.DataGrid’. [Line: 19 Position: 30]

Took me 30 minutes to see that

<Setter Property="VerticalGridlinesBrush">
    <Setter.Value>
        <SolidColorBrush Color="#FFACACAC"/>
    </Setter.Value>
</Setter>

should be

<Setter Property="VerticalGridLinesBrush">
    <Setter.Value>
        <SolidColorBrush Color="#FFACACAC"/>
    </Setter.Value>
</Setter>

Next time I need to hit ctrl+space sooner…