On my shaman, and only my shaman, the yellow quest progress text that pops up when you (for example) pick up a scroll for a quest and it shows you you’re at 4/13 or whatever in the top center of the screen, is missing. I’ve gone through all the UI options in-game, I’ve looked at the console command lists on Wowpedia, I’ve downloaded AdvancedInterfaceOptions, I can’t figure out which one would bring that text back. Anyone happen to know it? Thank you in advance!
Assuming Classic,
Esc.\Interface Options\Display\Automatic Quest Tracking.
Not classic, retail, I should’ve said that in my post, sorry. I’m not looking for the quest tracker on the right side of the screen, I’m looking for the text that pops up over your character’s head every time you make progress on a quest objective. 
Grab Advanced Interface Options, check out the Floating Combat Text section.
ObjectiveTrackerBonusBannerFrame - WORLD_QUEST_TRACKER_MODULE.
As far as I can tell, they should be on always. There’s no CVar for them.
If you:
/run print(WORLD_QUEST_TRACKER_MODULE.ShowWorldQuests)
It should show “true” if the world quests are being watched.
This does return “true”, but unfortunately doesn’t appear to be the setting I’m looking for. =/
Edit: @Elvenbane There’s nothing in there about the quest progression text…
Were you able to find a solution to this? Mine stopped showing up a few days ago and I haven’t been able to figure out how to turn it back on. Also on one toon only, and also returns “true” when I run that script.