This bug was originally marked as duplicate of bug 173252, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.

Build: NetBeans IDE Dev (Build 200911200201)
VM: Java HotSpot(TM) Client VM, 14.1-b02, Java(TM) SE Runtime Environment, 1.6.0_15-b03
OS: Windows XP, 5.1, x86

User Comments:
sunflower: - Refactor-> Rename the 'a' variable to 'c' in the code below
------------------------------------------------------------------------------
var a = 10;
var b = ( a + 10 ) / a;

println("a: {a}")
------------------------------------------------------------------------------
The exception pops up

sunflower: - Copy the attached code to the editor
- Go to the Scale class
- Refactor-> Rename the 'radiusScale' attribute to the 'radiusScale'

The error pops up.

sunflower: Steps to reproduce:
- Copy the code to the editor:
----------------------------------------------------------------------------------------------------------------------------
import java.lang.Comparable;

def INFINITY = Number.MAX_VALUE;

public function sign(y:Number):Integer {
    if( y <0 ) { -1 } else if(0 < y) { 1 } else { 0 }
}

class DVertex extends Comparable{

    //var vertex:Vertex;

    var value:Number;
    var previous:Integer;

    override function compareTo(obj:Object):Integer{
            var vertex = obj as DVertex;
            return sign(value - vertex.value);
    }

}

class Vertex{}
class Edge{}
class Graph{  var vertices:Vertex[] }

public function dijkstraShortestPath(source:Vertex, destination:Vertex, graph:Graph):Edge[]{


    var vertices = for(v in graph.vertices) DVertex{
        previous: indexof v
        value: if( v == source) then  0  else INFINITY
    };

    return [];
}
------------------------------------------------------------------------------



Stacktrace: 
java.lang.AssertionError
        at org.netbeans.modules.javafx.refactoring.impl.RenameRefactoringElement.init(RenameRefactoringElement.java:279)
        at org.netbeans.modules.javafx.refactoring.impl.RenameRefactoringElement.<init>(RenameRefactoringElement.java:101)
        at org.netbeans.modules.javafx.refactoring.impl.RenameRefactoringElement.create(RenameRefactoringElement.java:80)
        at org.netbeans.modules.javafx.refactoring.impl.plugins.RenameRefactoringPlugin.prepare(RenameRefactoringPlugin.java:383)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare2(AbstractRefactoring.java:419)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare(AbstractRefactoring.java:403)