Disable an action button.

Hi @development93,

You can disable the action in the RowSelected event. Below is an example, 

    public class APPaymentEntry_Extension : PXGraphExtension<PX.Objects.AP.APPaymentEntry>
    {
        #region Event Handlers

        protected void APPayment_RowSelected(PXCache cache, PXRowSelectedEventArgs e, PXRowSelected baseHandler)
        {
            baseHandler?.Invoke(cache, e);
            var row = (APPayment)e.Row;
            CAReconEntry.CATranExt ReconcileCheck = PXSelect<CAReconEntry.CATranExt,
                Where<CAReconEntry.CATranExt.origRefNbr, Equal<Required<APPayment.refNbr>>>>
                .Select(Base, Base.Document.Current.RefNbr);
            if (ReconcileCheck != null && ReconcileCheck.Reconciled == true)
            {
                Base.voidCheck.SetEnabled(false);
            }

        }
        #endregion
    }

The above query is to fetch CAReconEntry.CATranExt based on the Check and Payments RefNbr, you can update the query and condition below it to match your requirements.

Thanks,