Package as DMG Image fails with "typedef class com.sun.javafx.tools.ant.FXJar cannot be found using the classloader AntClassLoader[]"

Steps to reproduce:

1.  Install fresh copy of 11.3 (also tested with 11.1 with same results)

2 Create new Project "Java with Ant", "Java Application".

3.  Create a single Java file such as:

package testmacdmgwithant;

public class TestMacDMGwithAnt {

/**

• @param args the command line arguments
  */
  public static void main(String[] args) { int a=1; }

}

4. Go clean and build and debug to prove it works OK.

5. Run the .jar in the dist folder to prove it works OK.

6. Go right click on the project and select "Package as DMG Image"

End of output is:  .../NetBeansProjects/TestMacDMGwithAnt/nbproject/build-native.xml:519: typedef class com.sun.javafx.tools.ant.FXJar cannot be found
using the classloader AntClassLoader[]
BUILD FAILED (total time: 0 seconds)

7.  Note that this works fine on NetBeans 8.2 and also fails on 11.0..