I was wondering if this had happened to anyone else. Was doing a Companion quest that took me to Morvunskar and ran into an intersecting quest A night to remember. Well I got ported to Misty Grove and then finished that and had to come all the way back. Well after finishing the Companion quest and getting the item I was exploring and attempted to open two chests and when I did i was automatically ported to Misty Gove again. Thinking no big deal (but annoying) ill just get ported out and lo and behold there is no way out (kinda like that bad line for Lord of the Rings cept no orcs and trolls to kill to get out). Also note I haven't saved in oh say 6 or 7 hours.....had a major gaming binge going on today. I was wodnering is there a fix to this or is my file basically lost?

I had that too and thankfully had autosaves from when I entered the cave. Couldn't get out of there. The entrance was shown on the mini map, but wasn't actually there. Tried quick traveling as well, also no luck. So I just reloaded. Sorry to say, pal, but I fear you're screwed and will have to load your latest save. :[

Strange, i did the quest and it worked fine..
I know this isnt helpfull, just mentioning the bug could be random.

Right, the quest worked just fine, but even after completion the gate to Misty Grove was stll open. And when I accidently entered it a 2nd time I couldn't get out anymore. This happened in the same way for me as it did for the OP; trying to open the chest in the small room right underneath the gate and getting svcked in anyway.