Visual Studio 2012 Hangs while open Property Category

I'm creating a CategoryEditor for a UserControl. So my solution is made up of:

• UserControlProject
• UserControlProject.Design
• TestProject

My CategoryEditor should show a Button in the Property Grid for the category called "Common". The problem is that when I open the "Common" category for the UserControl placed in TestProject, Visual Studio hangs or I can't browse the Property Grid cause it's freezed.

This is my code (the most important parts):

The Category Editor:

internalclassQueryPropertyEditor:CategoryEditor{privateDataTemplate _dataTemplate;publicQueryPropertyEditor(){}publicoverride bool ConsumesProperty(PropertyEntry propertyEntry){//return propertyEntry.PropertyName == "Query" || propertyEntry.PropertyName == "OpcSession" || propertyEntry.PropertyName == "MaxRowsPerPage";returntrue;}publicoverrideDataTemplateEditorTemplate{
        get {return _dataTemplate ??(_dataTemplate =newDataTemplate{VisualTree=newFrameworkElementFactory(typeof(QueryEditorButton))});}}publicoverrideobjectGetImage(Size desiredSize){returnnull;}publicoverridestringTargetCategory{
        get {return"Common";}}}

Metadata.cs:

internalclassMetadata:IProvideAttributeTable{// Accessed by the designer to register any design-time metadata.publicAttributeTableAttributeTable{
        get{AttributeTableBuilder builder =newAttributeTableBuilder();

           builder.AddCustomAttributes(typeof(Col.HMI.Controls.Summary),newEditorAttribute(typeof(QueryPropertyEditor),typeof(QueryPropertyEditor)));return builder.CreateTable();}}}

The QueryEditorButton.xaml:

<UserControl x:Class="ColScadaControls.Design.QueryDesigner.QueryEditorButton"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"><StackPanel><TextBlockMargin="16,0"><HyperlinkClick="EditQueryClick">EditQuery...</Hyperlink></TextBlock></StackPanel></UserControl>

The QueryEditorButton.xaml.cs:

[ToolboxBrowsable(false)]publicpartialclassQueryEditorButton{publicQueryEditorButton(){InitializeComponent();}
}