Value cannot be set in BEFORELOAD on already existing (not a new) record.

AI generated answer (using internal Slack threads):

****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ****** The error you're encountering, "Value cannot be set in BEFORELOAD on already existing (not a new) record", is due to the fact that in NetSuite's SuiteScript, you cannot update an existing field in the

beforeLoad

event. This event is triggered when a record is loaded into memory, and at this point, the record is read-only. The

beforeLoad

event is typically used for adding new fields or sublists to a form, or for setting default values on a new record. However, it cannot be used to modify existing fields on an existing record. If you need to modify a field value on an existing record, you should move your logic to the

beforeSubmit

event. In this event, you can access the

newRecord

object and use the

setValue

method to update the field value. Here's a basic example of how you might do this:

javascript
function beforeSubmit(context) {
    var newRecord = context.newRecord;
    newRecord.setValue({
        fieldId: 'your_field_id',
        value: 'your_new_value'
    });
}

Remember, the only time you can set a value in

beforeLoad

is if you're adding the field first, and that field would start with the internalid id of "custpage". If you want to edit a record in view mode, you will have to use

record.load(options)

then use

record.setValue(options)

and then

record.submit(options)

. Please note that this is a general guidance and you may need to adjust the code to fit your specific needs.