I'm using Java FX 8 and Scene Builder 8.5.0 and I have a problem with adding custom LineChart control without fxml. When I'm importing this control in the SceneBuilder there is empty "Import dialog" window but in the "Library Manager" window this control is displayed as installed "Libraries/FXML Files". Scene Builder displays "Unresolved class CustomControlClass". I have tried with different custom controls.
Additionally after pressing this custom control in the "Hierarchy" tab then on the right side tabs (Properties, Layout and Code) there is error: "Selection contains unresolved reference".