How to randomize bot response in small talk?

I was following this blog to create a randomized bot response

TechExchange Quick-Tip: How To Create Randomized Bot Responses Using Resource Bundles in Oracle Digital Assistant

So I created messages in my resource bundle (yes I realize the _00 is not really useful .. I also noticed you cannot remove keys from the resource bundle once you've created them :-( )

Create a flow that handles a specific intent to respond on personality (000 to 003)

But I get this error

Now to show you it should work I've changed the PersonalizeMsg to this ..

Testing

Personality_00${.now?long % 4}

Demo

0: ${rb('Personality_000')}

1: ${rb('Personality_001')}