Is there anything wrong with the following code:
<Panel ux:Class="MyButton" FontSize="20" Background="#55ACEE" TextColor="#fff" TextAlignment="Center">
<string ux:Property="Text" />
<string ux:Property="TextAlignment" />
<float ux:Property="FontSize" />
<Brush ux:Property="TextColor" />
<Rectangle Name="rect" Background="{Property this.Background}" Padding="{Property this.Padding}">
<Text Alignment="Center" TextAlignment="{Property this.TextAlignment}" TextWrapping="Wrap" TextColor="{Property this.TextColor}" Font="RobotoMedium" FontSize="{Property this.FontSize}" Value="{Property this.Text}" />
</Rectangle>
<WhileEnabled>
<WhilePressed>
<Change Target="rect.Background" Value="#3895DB" />
</WhilePressed>
</WhileEnabled>
<WhileDisabled>
<Change Target="rect.Background" Value="#A1A1A1" />
</WhileDisabled>
</Panel>
Running on the latest version 0.12.0 (build 6286)