Friedman and Ranzenhofer, PC Law Blog, New York Estate Planning & WillsWHAT ARE THE GROUNDS FOR CONTESTING A NEW YORK WILL? NY Wills can be contested on the grounds of lack of due execution or testamentary capacity, undue influence and/or duress. WHAT IS A CODICIL? HOW IS LACK OF DUE EXECUTION PROVEN BY A NEW YORK OBJECTANT?