title: The property 'Content' is set more than once Button WPF
body: <p>I've read some other answers, but I can't quite fathom out why mine is still throwing this error:</p>
  
  <pre><code>&lt;Grid Grid.Column="2" Width="100" Height="30" HorizontalAlignment="Right"&gt;
              &lt;Grid.ColumnDefinitions&gt;
                  &lt;ColumnDefinition Width="*" /&gt;
                  &lt;ColumnDefinition Width="*" /&gt;
                  &lt;ColumnDefinition Width="*" /&gt;
                  &lt;ColumnDefinition Width="*" /&gt;
              &lt;/Grid.ColumnDefinitions&gt;
  
              &lt;Button Command="{Binding CloseCommand}" Grid.Column="3" Width="24" Height="24" HorizontalAlignment="Right"&gt;
                  &lt;Button.Template&gt;
                      &lt;ControlTemplate TargetType="{x:Type Button}"&gt;
                          &lt;StackPanel&gt;
                              &lt;Image Source="{Binding LocalisedResource[delete_48.png].Image}" Stretch="Fill" VerticalAlignment="Top" /&gt;
                          &lt;/StackPanel&gt;
  
                          &lt;ControlTemplate.Triggers&gt;
                              &lt;Trigger Property="IsMouseOver" Value="True"&gt;
                                  &lt;Setter Property="Cursor" Value="Hand" /&gt;
                              &lt;/Trigger&gt;
                          &lt;/ControlTemplate.Triggers&gt;
                      &lt;/ControlTemplate&gt;
                  &lt;/Button.Template&gt;
              &lt;/Button&gt;
              &lt;Button Command="{Binding ShowConfigCommand}" Grid.Column="0" Width="24" Height="24" HorizontalAlignment="Right"&gt;
                  &lt;Button.Template&gt;
                      &lt;ControlTemplate TargetType="{x:Type Button}"&gt;
                          &lt;StackPanel&gt;
                              &lt;Image Source="{Binding LocalisedResource[software_24.png].Image}" Stretch="Fill" VerticalAlignment="Top" /&gt;
                          &lt;/StackPanel&gt;
  
                          &lt;ControlTemplate.Triggers&gt;
                              &lt;Trigger Property="IsMouseOver" Value="True"&gt;
                                  &lt;Setter Property="Cursor" Value="Hand" /&gt;
                              &lt;/Trigger&gt;
                          &lt;/ControlTemplate.Triggers&gt;
                      &lt;/ControlTemplate&gt;
                  &lt;/Button.Template&gt;
              &lt;/Button&gt;
          &lt;/Grid&gt;
  </code></pre>
  
  <p>People aren't getting this error, so I will post the rest of the code:</p>
  
  <pre><code>&lt;Grid&gt;
          &lt;Grid.Background&gt;
              &lt;SolidColorBrush Color="Black" /&gt;
          &lt;/Grid.Background&gt;
  
          &lt;Grid.ColumnDefinitions&gt;
              &lt;ColumnDefinition Width="20" /&gt;
              &lt;ColumnDefinition Width="*" /&gt;
              &lt;ColumnDefinition Width="*" /&gt;
              &lt;ColumnDefinition Width="20" /&gt;
          &lt;/Grid.ColumnDefinitions&gt;
  
          &lt;Grid.RowDefinitions&gt;
              &lt;RowDefinition Height="50" /&gt;
              &lt;RowDefinition Height="*" /&gt;
              &lt;RowDefinition Height="*" /&gt;
              &lt;RowDefinition Height="20" /&gt;
          &lt;/Grid.RowDefinitions&gt;
  
  
          &lt;TextBlock Text="{Binding LocalisedText[app.title]}" Grid.Column="1" Grid.Row="0" Style="{DynamicResource MainWindowTitleTextStyle}" /&gt;
  
          &lt;Grid Grid.Column="2" Width="100" Height="30" HorizontalAlignment="Right"&gt;
              &lt;Grid.ColumnDefinitions&gt;
                  &lt;ColumnDefinition Width="*" /&gt;
                  &lt;ColumnDefinition Width="*" /&gt;
                  &lt;ColumnDefinition Width="*" /&gt;
                  &lt;ColumnDefinition Width="*" /&gt;
              &lt;/Grid.ColumnDefinitions&gt;
  
              &lt;Button Command="{Binding }" Grid.Column="3" Width="24" Height="24" HorizontalAlignment="Right"&gt;
                  &lt;Button.Template&gt;
                      &lt;ControlTemplate TargetType="{x:Type Button}"&gt;
                          &lt;StackPanel&gt;
                              &lt;Image Source="{Binding LocalisedResource[delete_48.png].Image}" Stretch="Fill" VerticalAlignment="Top" /&gt;
                          &lt;/StackPanel&gt;
  
                          &lt;ControlTemplate.Triggers&gt;
                              &lt;Trigger Property="IsMouseOver" Value="True"&gt;
                                  &lt;Setter Property="Cursor" Value="Hand" /&gt;
                              &lt;/Trigger&gt;
                          &lt;/ControlTemplate.Triggers&gt;
                      &lt;/ControlTemplate&gt;
                  &lt;/Button.Template&gt;
              &lt;/Button&gt;
              &lt;Button Command="{Binding }" Grid.Column="0" Width="24" Height="24" HorizontalAlignment="Right"&gt;
                  &lt;Button.Template&gt;
                      &lt;ControlTemplate TargetType="{x:Type Button}"&gt;
                          &lt;StackPanel&gt;
                              &lt;Image Source="{Binding LocalisedResource[software_24.png].Image}" Stretch="Fill" VerticalAlignment="Top" /&gt;
                          &lt;/StackPanel&gt;
  
                          &lt;ControlTemplate.Triggers&gt;
                              &lt;Trigger Property="IsMouseOver" Value="True"&gt;
                                  &lt;Setter Property="Cursor" Value="Hand" /&gt;
                              &lt;/Trigger&gt;
                          &lt;/ControlTemplate.Triggers&gt;
                      &lt;/ControlTemplate&gt;
                  &lt;/Button.Template&gt;
              &lt;/Button&gt;
          &lt;/Grid&gt;
  
          &lt;!-- Popup Box --&gt;
          &lt;ContentPresenter Content="{Binding }" Grid.Column="1" Grid.ColumnSpan="4" Grid.Row="2" Grid.RowSpan="4" VerticalAlignment="Center" HorizontalAlignment="Center" /&gt;
  
          &lt;!-- Connected View Goes Here --&gt;
          &lt;ContentPresenter Content="{Binding }" Grid.Column="1" Grid.Row="1" /&gt;
  
          &lt;!-- Demo View Goes Here --&gt;
          &lt;ContentPresenter Content="{Binding }" Grid.Column="1" Grid.Row="2" /&gt;
  
          &lt;!-- Configuration --&gt;
          &lt;ContentPresenter Content="{Binding }" Grid.ColumnSpan="2" Grid.RowSpan="2" Grid.Row="1" Grid.Column="1" Margin="50" /&gt;
      &lt;/Grid&gt;
  </code></pre>