Here is my code which does not work:

[RibbonGroup("ProjectsViewSampleActionGroup2", "Test", ContextByType = typeof(ProjectsController))]
[RibbonGroupLayout(LocationByType = typeof(TranslationStudioDefaultRibbonTabs.EditorReviewRibbonTabLocation))]
public class ProjectsViewSampleActionGroup : AbstractRibbonGroup
{
}

[Action("ProjectsViewSampleAction2", typeof(ProjectsController), Name = "ProjectsViewSampleAction_Name2", Description = "Meine Beschreibung", Icon = "ProjectsViewSampleAction_Icon")]
[ActionLayout(typeof(ProjectsViewSampleActionGroup), 1, DisplayType.Large)]
[ActionLayout(typeof(TranslationStudioDefaultContextMenus.EditorDocumentContextMenuLocation),1,DisplayType.Large)]
[Shortcut(Keys.Alt | Keys.F8)]
public class ProjectsViewSampleAction : AbstractViewControllerAction<ProjectsController>
{

protected override void Execute()
{...}
}