How to Debug a builtin function. i want to debug the delete action of soinvoice screen.

ok for those who will come through google in future.

i indeed found graph extension of both arinvoiceEntry and soInvoiceEntry,
when i commented both of them the error is gone and it could be deleted normally,

then i traced the code bit by bit till i found which part was the cause of the error and it somehow ended up being some views

precisely those.

        public PXSelect<ARRegister, Where<ARRegister.refNbr, Equal<Required<ARRegister.refNbr>>, And<ARRegister.docType, Equal<Required<ARRegister.docType>>>>> document;
        public PXSelect<SOOrder, Where<SOOrder.orderNbr, Equal<Required<SOOrder.orderNbr>>, And<SOOrder.orderType, Equal<Required<SOOrder.orderType>>>>> order;

i removed document view because it wasn’t used
and replace order view with 
PXSelect<SOOrder, Where<SOOrder.orderNbr, Equal<Required<SOOrder.orderNbr>>, And<SOOrder.orderType, Equal<Required<SOOrder.orderType>>>>>.Select(Base,orderNbr, orderType);
in the event handlers

and it worked.