Created attachment 88835 [details]
stacktrace

Steps to reproduce:

- Create the 'MyCustomNode' JavaFX class under the 'pack' package:
-------------------------------------------------
import javafx.scene.CustomNode;
import javafx.scene.Group;
import javafx.scene.Node;

public class MyCustomNode extends CustomNode {

	public override function create(): Node {
		return Group {
			content: []
		};
	}
}
-------------------------------------------------

- Create the Main JavaFX file under the 'javafxapplication9' package

-------------------------------------------------
import javafx.stage.Stage;
import javafx.scene.Scene;

import pack.MyCustomNode;

Stage {
    title: "Application title"
    width: 250
    height: 80
    scene: Scene {
        content:  MyCustomNode{}
        
    }
}
-------------------------------------------------


- Right-click the 'MyCustomNode' class name in the 'content:  MyCustomNode{}' line,
  and select Refactor->Rename
- Add '2' after the 'MyCustomNodes' name in the Rename dialog

The exception pops up.

fixed in http://hg.netbeans.org/javafx/rev/837f9fc199dc

verified in netbeans-trunk-nightly-200910080418-javafx-full.zip