Jason_the_Iguana: Sorry, no. I don't know.
Which quest are you talking about, exactly?
This is the NWN2 official campaign?
What's supposed to happen, and what exactly goes wrong? Have you checked a walkthrough to see what should happen at this point?
I'd like to help, but you need to describe your problem in much more detail.
Axinas: Yes it's the first official campaign, it's the second act where you have to prove that you didn't destroy this city in Luskar. You have to serve a Knight and for that you have to stay a Night on this Glade. I have seen a Walktrough and normally there should be a cutscene after you kill the Assassins, but nothing happens by me.
Hm.. tricky. Shandra should indeed talk to you at that point. It seems likely a variable got messed up, but I don't know which one.
I recommend asking the same question here:
http://forum.bioware.com/forum/152-technical-support/
The people there are much more technically savvy and hopefully will be able to figure out how you can fix this with the console.
Edit: In fact, searching that forum there's a long thread on someone with the exact same problem. Check this out for more tips:
http://forum.bioware.com/topic/147979-game-broken-at-the-vigil/?hl=%2Bsquire#entry3936642 Edit 2: This seems like your best bet. Enter the console (~ key, usually) and type:
DebugMode 1
rs 20a_start_vigil2
DebugMode 0
Credit to kevL on the Bioware tech support forum in that thread.