No, that's an RMXP standard function. You don't need a messaging system for it.
Things to check - what number are you using for the actor?
Does your name input processing refer to the correct actor number, and does it allow enough characters?
You're outputting it using Show Text?
I created a 9th character in the default project, used #9 for name input processing, and I tried all of the following:
Show Text: Hello \N[9]
Show Text: Hello \N[009]
Show Text: Hello \n[9]
Show Text: Hello \n[009]
and they all worked.
Do you HAVE a custom message system installed in your scripts - if so, could that be interfering?
You say "nothing" comes out. Does that mean you don't even get a message box? Or do you get a message box, but it's empty? Or does it have something in it, but just not the name?
Can you tell us what you're outputting in the Show Text command, and tell us exactly what you see when it hits that logic?