Not a big deal as it's only a miscellaneous quest.

Recover Nesbits goods ( Markath misc quest )

Only I can't, because the door won't open....so reading the Wiki I also realize she will next ask you to recover a statute, which I already found somewhere else. Did this break the quest ? As when I first entered the dungeon I got a sound almost like I leveled up or a script ( Like text message was supposed to appear or voice over ) was firing, Only it wasn't firing. Neither did I level in any skill even though it sorta sounded like I did( Checked all before entering )
I then gave the statute to Lydia and it didn't do it. It did not make any weird sound while Lydia had it ,but the door still didn't open
Maybe if I leave it at home.?

Definitely not worth loading an old save and as long it doesn't affect main quests.

I'm already stuck with quest unfinished if you already had previously cleared the area bug . Not too bad though ,as I always ask everyone now for quests and this highlights a lot of unknown places.

Just wondering if there is any phat loot behind that door ? I ended up loading a save way before I entered the cavern and just bypassing it until I figure it out ( Door opening bit )