Problem with Clone function generated from SNACC

Hello

I am getting a lot of these compile errors:
error C2259: 'PublicTON' : cannot instantiate abstract class due to
following members: csta2less.h(1755) : see declaration of 'PublicTON'

Class is like this:
class PublicTON: public AsnType

generated .h file:
AsnType *Clone() const;

generated .cpp file:
AsnType *PublicTON::Clone() const
{
    return new PublicTON(*this);
}

There are LOTS of these clone functions in lots of other classes which cause
this problem.  I am running eSNACC v1.6 on Windows platform.

How can I manually edit clone function so it compiles ok?

Angus