Consider the following code:
enum Test {
    A {};
}

The "A {}" is modeled as a field whose initializer is a NewClassTree, containing a ClassTree as its ClassBody. Currently, the NewClassTree's starting position is:
    A {};
      ^
but the embedded ClassTree's position is:
    A {};
    ^

Which confuses the NetBeans code generator, as the inner tree is outside the bounds of the outer tree. I propose this position is changed to:
    A {};
      ^

Similarly for enum constants with parameters, the NewClassTree's position would be kept as
    A (1) {};
      ^
and the ClassTree's position would be:
    A (1) {};
          ^