NPC dialog shows up in its own channel. Maybe you don't have it in your chat tab?
Avatar: "Cheeky Jack O Lantern" by dimarie
So no text bubbles over the heads?
Sonofa...
Gonna go see if that works.
Very strange scenario. Seems almost like the opposite of the problems most people have, which is inactive and active text all popping up at once, and the bosses using the default punching-hand starting animation.
Wish I knew how to help you, aside from testing your arc personally. And even then, I can't guarantee I'd be able to help fix it.
So..that worked.
I'm currently adding this to my long list of "there are no stupid questions...only stupid people" posts 
I posted on this a few days ago. Sorry for the repeat but my original post was rather vague.
I hope that someone can help me with the following problem:
None of the dialog text that is to be spoken by the various NPCs appears in my arcs.
So for example - on the Mission Details screen There are several sub-fields in the BOSS TEXT section e.g.: Boss Unaware Dialog, Boss 1/2 Hetlah, etc.
When I come near the boss he is in his correct Starting Animation as is the group surrounding him. The mission otherwise plays as anticipated but the Dialog text just isn't showing up.
None of script that I have typed into any of these files or any of the other fields like them for patrols, allies, etc are actually spoken by the NPCs in-game.
I deleted my initial arc and started over but am having the same problem. Therefore it's likely just a very odd bug or (perhaps more likely) something that I should be doing differently.
Any help would be appreciated.
Thanks,
Marsh