Hi How can we Disable the 'discount' sublist(item) field on the transaction record using UES before load event?

if this is only applicable for the UI, you could create a saved search on items and exclude all with type = discount. then you add the saved search to your transaction forms as an item filter (the "sublist fields" tab)

@mesper Thanks for the reply, The actual issue is that the custom sublist field is locked that's why my UES is not disabling the field.