#1 - The "Aberian's Folly" section of page 32 reads," Doors are of heavy oak and carved with images of capering devils (DC 30 Disable Device to open when locked; DC 26 Strength check to break down)"
#2 - The description for "Crosael's Chambers" (room A9 on page 34) states, "Although she keeps both doors locked at all times, she knows better than to keep evidence of her tiefling heritage here. A small cabinet at the foot of her bed is also locked (DC30 Disable Device to open)". Since there's no specific DC given for Crosael's doors the statement in #1 would cause me to assume that they're probably supposed to be DC30.
#3 - The DC30 locked cabinet in Crosael's DC30 locked room contains an iron key to open the locked door in the Main Attic (A45 on page 36). Per the description for room A45 that door is also DC30 though the description for the adjacent room (North Attic A51 on page 37) says that the lock if DC35.
Assuming the DC30 values are correct there's little point infiltrating Crosael's DC30 room to get into her DC30 cabinet and obtain the key to the DC30 lock in the attic. I guess if the attic lock is really DC35 like room A51 says then there's a point if your PCs can hit DC30 but not DC35 on Disable Device. My PCs couldn't even hit DC30 though, so the entire adventure almost fell apart. On the fly I ruled that the locks on Crosael's room were only DC25, and the PCs had a little adventure stealthily hauling the "small cabinet" out of Crosael's room through the nearby Servant Entrance to an area behind the stables. Out there they smashed their way in though they were nearly caught by the improvised stable boy NPC and his improvised dog before sneaking back into the mansion and finally, finally making their way into the North Attic to find the Asmodean Knot.
Overall I think the players had fun and might not even know that I fudged things a little to make the adventure work. I wonder how things are "supposed" to work when the party doesn't have anybody who can hit DC30 on Disable Device though. I mean, maybe the players should have invested more heavily in that skill since the AP is called "Council of THIEVES", but apparently +7 is the best anybody could come up with (+9 with masterwork tools still wouldn't be quite enough)
I read over last night's section of the adventure again, and I didn't see anything where NPCs give the party a magic item which might help or maybe a key that I might have missed. I guess I could have made Calseinica suddenly and inexplicably good at opening locks or perhaps had one of the other NPCs offer to help, but the fact that the adventure only seemed to offer one obvious path to success (make a DC30 Disable Device check) seemed surprising to me.
...apparently +7 is the best anybody could come up with (+9 with masterwork tools still wouldn't be quite enough).
Is that +7 with Aid Another, or did you only have 1 character with Disable Device?
There was just one PC trained in Disable Device. Why the party wasn't better at what seems like a key skill for this campaign is something I've already asked the players, but I wish the module would have included some information on alternate solutions to advance the story or at least the likely results of the PCs breaking down doors in the mansion.
Maybe the Cornucopia celebration is so noisy that nobody would hear a door being chopped down in the attic, or maybe I should have suggested that the attic is so infrequently accessed that the party might have been able to hide up there long enough to regain spells and memorize Silence. Having some guidance on this stuff or suggestions for other ways the PCs might get into the North Attic and access the Asmodean Knot might have been pretty helpful. I thought maybe there was something in the module which I missed, but I guess maybe not.
The fact that we had our own little "Cornucopia" celebration around the table might have made it a little easier to miss something. Some Gnarly Head old vine zinfandel (red, not white) stood in for "The Blood" wine served to the guests , and our main course of "roast Gorgon" (aka prime rib) was served with "Gorgon's Breath" (absinthe with water). The "Baby Chuul" (shrimp cocktail) was pretty tasty too but didn't actually numb our mouths with paralytic poison (though perhaps it could have with some Szechaun peppercorn in the cocktail sauce...)