title: "Property Get method was not found" error on OnPropertyChanged
body: <p>I get the error </p>
  
  <blockquote>
    <p>Additional information: Property Get method was not found when invoking OnPropertyChanged.  </p>
  </blockquote>
  
  <p>The idea is that I have a <code>ListView</code> with multiple items to select and <code>SelectionMode="Multiple"</code>. Everytime an item is clicked in the <code>ListView</code> I want to add it to an <code>ObservableCollection&lt;Inspection&gt;</code>. </p>
  
  <p>For the time being I'm doing it as so:</p>
  
  <p>Xaml:</p>
  
  <pre><code>&lt;ListView x:Name="Reports"
                    Margin="0,5,0,0"
                    RelativePanel.Below="ListViewHeader"
                    SelectionMode="Multiple"
                    ItemsSource="{Binding inspectionCatalogSingleton.Inspections}"
                    SelectedItem="{Binding SelectedInspections, Mode=TwoWay}"&gt;
  &lt;/ListView&gt;
  </code></pre>
  
  <p>ViewModel:</p>
  
  <pre><code>public ReportViewModel()
  {
      _selectedInspections = new ObservableCollection&lt;Inspection&gt;();
  }
  
  private ObservableCollection&lt;Inspection&gt; _selectedInspections; 
  public Inspection SelectedInspections
  {
      set
      {
          _selectedInspections.Add(value);
          OnPropertyChanged();
      }
  } 
  
  /*....*/
  
  public event PropertyChangedEventHandler PropertyChanged;
  
  [NotifyPropertyChangedInvocator]
  protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
  {
      PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
  }
  </code></pre>
  
  <p>I've set a breakpoint at the set part of the property and it enters fine however when i click continue the error rises at this line:  </p>
  
  <pre><code>PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
  </code></pre>
  
  <p>What am I doing wrong here?</p>