Error in XAML - The TypeConverter for "Style" does not support converting from a string

I have a textbox that I want to be watermarked. In my window.resources section I added the style included in its entirety below. When I set the style on the textbox, Blend 3 Beta displays the following message: 'The TypeConverter for "Style" does not support converting from a string' What is going on and how do I fix this? ``` <Style x:Key="WaterMarkTextBoxStyle" BasedOn="{StaticResource {x:Type TextBox}}" TargetType="{x:Type TextBox}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type TextBox}"> <Grid> <ScrollViewer x:Name="PART_ContentHost" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" /> <TextBlock x:Name="textBlock" Opacity="0.345" Text="Enter Text Here" TextWrapping="Wrap" Visibility="Hidden" /> </Grid> <ControlTemplate.Triggers> <MultiTrigger> <MultiTrigger.Conditions> <Condition Property="IsFocused" Value="False" /> <Condition Property="Text" Value="" /> </MultiTrigger.Conditions> <Setter Property="Visibility" TargetName="textBlock" Value="Visible" /> </MultiTrigger> </ControlTemplate.Triggers> </ControlTemplate> </Setter.Value> </Setter> </Style> ```