Copying an existing Unifi trigger rule doesn't work

If you're looking to integrate a new table with Unifi (prior to v3 as this is then done automatically), and you create a new trigger business rule for the new table from an existing Unifi trigger rule, be careful with what you copy! Old business rules use a different way to invoke the script from new ones!
Overwriting a new business rules invoke method with an old one will mean the business rule fails. Only copy the Unifi code inside the business rule invoke method.
Old business rule invoke:
function onBefore(current, previous) {
New business rule invoke method:
(function executeRule(current, previous /*null when async*/) {
})(current, previous);