ok got to Pogahn passage mission- rescued the prisoners, got the item, it says 'escape from the fortress'- so I fight back out the front gate, back to mission start, mission doesn't end- timer still running.
Finally discover too late that there is a dock with a ship on it, and supposed to use this- too many enemies including a lvl 24 ele boss, boom and prisoner is dead, mission failed, half hour wasted.
Put some guidance in this mission!!!! Waypoints or even 'discover an alternative means of escaping the fortress' would have saved me from wasting so much time.
So many of the missions have large areas with bonuses like 'destroy all 12 guard towers' , then NO indication of where any of them are, and you waste valuable playing time crisscrossing entire areas to find whatever it is you're looking for.
The simple addition of waypoints, or some pointers in the mission logs, would make Nightfall so much more enjoyable for all of us- at the moment it looks like too many of these were rushed without thought of playability.
Mission problems
Victory
Lem
actually there is, on the mission you mention and on a lot of them there are markers on the map you bring up by pressing U.
all 12 guard towers are marked by flags on there.
all 12 guard towers are marked by flags on there.
Knightsaber Sith
I still can't find the Pogahn passage bonus. It says there are five side objectives you have to do but I can only find three
get the password for the prison
kill the demon
and escort sunspears to the prison
get the password for the prison
kill the demon
and escort sunspears to the prison
Phaern Majes
ditto... I used support to ask a question, but you know how that goes
Luciora
Also got the 3/5 for Pogahn
A guildie and I started the mission, ran around EVERY where outside, inside. Got Prisoners and did the same, open prison gates then ran around again. NOTHING 
Mordok Crevice also has me at a loss. I get 2/4 of the advice bits but then nothing
Mordok Crevice also has me at a loss. I get 2/4 of the advice bits but then nothing