RadRichTextBox: System.InvalidOperationException: 'Cannot use a DependencyObject that belongs to a different thread than its parent Freezable.' when having multiple instances in separate threads
System.InvalidOperationException: Cannot use a DependencyObject that belongs to a different thread than its parent Freezable. is thrown when multiple RadRichTextBoxes are instantiated in different STA threads. The cause seems to be a static freezable resource.