Problems with Visibility Binding in DataTemplate
<p>I don't know why but my Visibility Binding isn't working ONLY in the DataTemplate. Did I forget something?
Edit: All Bindings (except for this one work perfectly)
Thats the structure.</p>

<pre><code>&lt;Window&gt;
&lt;Grid&gt;
&lt;Grid&gt;
&lt;Grid Grid.Row="5"&gt;
                &lt;Grid.RowDefinitions&gt;
                    &lt;RowDefinition Height="Auto" /&gt;
                    &lt;RowDefinition Height="Auto" /&gt;
                &lt;/Grid.RowDefinitions&gt;                
                  &lt;ItemsControl x:Name="Targets" Margin="0,4,0,4"&gt;
                    &lt;ItemsControl.ItemTemplate&gt;
                        &lt;DataTemplate&gt;
                            &lt;Grid Margin="0,5,0,5"&gt;
                                &lt;Grid.ColumnDefinitions&gt;
                                    &lt;ColumnDefinition Width="*" /&gt;
                                    &lt;ColumnDefinition Width="Auto" /&gt;
                                    &lt;ColumnDefinition Width="Auto" /&gt;
                                &lt;/Grid.ColumnDefinitions&gt;
                                &lt;Grid.RowDefinitions&gt;
                                    &lt;RowDefinition Height="Auto" /&gt;
                                    &lt;RowDefinition Height="Auto" /&gt;
                                &lt;/Grid.RowDefinitions&gt;

                                &lt;TextBox TextWrapping="Wrap" Foreground="{Binding Foreground, NotifyOnSourceUpdated=True, UpdateSourceTrigger=PropertyChanged}" Text="{Binding Address, UpdateSourceTrigger=PropertyChanged, NotifyOnSourceUpdated=True}" Tag="{Binding}" PreviewKeyDown="ChangeLocationAddress" PreviewGotKeyboardFocus="TxtGotKeyboardFocusHandler" LostKeyboardFocus="ChangeLocationAddress" /&gt;
                                &lt;Button Margin="2,0,0,0" Grid.Column="1" Content=" ↑ " Click="MoveLocationUp" Visibility="Visible" /&gt; 
                                &lt;Button Margin="2,0,0,0" Grid.Column="2" Content=" ↓ "  Click="MoveLocationDown" Visibility="{Binding Path = UpDownButtonVisibility, UpdateSourceTrigger=PropertyChanged}"/&gt;
                            &lt;/Grid&gt;
                        &lt;/DataTemplate&gt;
                    &lt;/ItemsControl.ItemTemplate&gt;
                &lt;/ItemsControl&gt;
           &lt;Button x:Name="btnNewAddress" Grid.Row="1" Content="Neues Ziel hinzufügen" Margin="0,4,0,4" Visibility="{Binding Path=TargetButtonVisibility}"/&gt;
        &lt;/Grid&gt;
&lt;/Grid&gt;&lt;/Grid&gt;&lt;/Grid&gt;&lt;/Window&gt;
</code></pre>

<p>Codebehind:</p>

<pre><code>public MapView(){
 this.DataContext = this.ViewModel = new MapVM();
 this.InitializeComponent();
 this.Targest.Itemssource = this.ViewModel.ToLocations;
}
</code></pre>

<p>ViewModel:</p>

<pre><code>public MapVM()
        {   this.UpDownButtonVisibility = Visibility.Collapsed;
            this.TargetButtonVisibility = Visibility.Collapsed;
        }
 private Visibility _UpDownButtonVisibility;
    /// &lt;summary&gt;
    /// Property Visibility für "↓" und "↑"
    /// &lt;/summary&gt;
    public Visibility UpDownButtonVisibility
    {
        get { return _UpDownButtonVisibility; }
        set
        {
            this._UpDownButtonVisibility = value;
            NotifyPropertyChanged("UpDownButtonVisibility");
        }
    }
public Visibility TargetButtonVisibility { get; set; }
</code></pre>

<p>EDIT:
Program Output:
    BindingExpression path error: 'UpDownButtonVisibility' property not found on 'object' ''Location' (HashCode=-794088449)'. BindingExpression:Path=UpDownButtonVisibility; DataItem='Location' (HashCode=-794088449); target element is 'Button' (Name=''); target property is 'Visibility' (type 'Visibility')   1.10s       </p>

<p>Any suggestions?</p>