Getting Units of Measure values (SuiteScript)

For a script I'm writing, I need to get some values form the Units of Measure table.

When I use currentRec.getCurrentSublistValue  I receive back an ID.

Thereafter I execute a search because the recordtype of a unitstype is a list and not a entity, therefore a  Record.Load({}) should not work.

However, when I use the script I created, I get the following error in the UI:

the internalid is not valid, the same counts for the externalid:

These fields should be usable according to the Record Browser

Can somebody tell me what I'm doing wrong?

 * @NApiVersion 2.0
 * @NScriptType ClientScript
 * @NModuleScope SameAccount
 */
// Changelog
// 
// 
// 
// Einde changelog


define(['N/currentRecord', 'N/record', 'N/log', 'N/search'],
/**
 * 
 * @param currentRecord
 * @param record
 * @param log
 * @param search
 * @returns
 */
		
 function(currentRecord, record, log, search) {
    function fieldChanged(context) {
    	
    	// Gegevens in variabelen wegschrijven voor later gebruik
    	var currentRec = context.currentRecord; // Huidige record
    	var sublistName = context.sublistId;
    	var sublistFieldName = context.fieldId; // Huidig veld wat de fieldchanged aanroept
    	var line = context.line; // Huidige regel


    	// Als het huidig gewijzigde veld UNITS TYPE UOM is, voer het volgende uit
    	if (sublistName === 'item' && sublistFieldName  === 'custcol_schutte_uom_ut'){
    		log.debug({message:'wel