I'm pretty sure a lot of us has had the same exact problem as me.
During one of the main Dragonborn story missions, there comes a time when you have to free certain people from Miraaks spell at a stone. When you do, a huge golem pops out and tries to kill everything. I'm one of those perfectionists, so i didn't let anyone die from it. SO i was good, for that point in time. Later on in the quest line, you come to a village where you see Finari Strongvoice and Deor Woodcutter arguing about something.
Now, if you're trigger happy with the controls, you'll interrupt their conversation. Not knowing this, i was trigger happy and interrupted the conversation. I went down to the dialogue option that says "Did I overhear someone went missing?" and then FInari answers back what she always does. Then i tried to engage Deor in conversation and he keeps talking nonsense about how the Red Mountain explosion messed everything up. Therefore not allowing me to ge the quest to save the Blacksmith and get the Stalhrim armor. I Didn't know this at the time and finished the main story line and pretty much beating everyother quest known in the Dragonborn DLC.
The only one i haven't done is the one to kill the werebear brother of one of the villagers.
So pretty much i have two options, 1. to forget about the Stahlrim armor, and 2. to reset all progress i've made throught the DLC and not be trigger happy. Which i won't do.
Can someone give me a fix or can Bethesda do something.
Note*: I've beaten literally every single mission besides the werebear thing, including the main story line.