Error invoking an helper function ( 7.8)


I have parameter into a UIViewDefinitionList that uses a helper function - “funk”: “otherServicePointForSameTaxNumber”,

                    "id": "moreServicePoint",
                    "label": "{~RevenueProtection.Detail.DetailTabs.DetailsLocation.OpportunityDetail.rows.moreSPforTaxNumber.label~}",
                    "field": "",
                    "format": {
                        "funk": "otherServicePointForSameTaxNumber",
                        "args": [

When the page is loaded I do not see any call to the function and moreover also the label RevenueProtection.Detail.DetailTabs.DetailsLocation.OpportunityDetail.rows.moreSPforTaxNumber.label is not shown neither in italian or english - I see an error on console “Callback was already called.” since in this helper function a UINetworkC3Request is sent. What could be the reason of the callback error?