Sorry to all that are experiencing this, but there simply are some issues left in the game. They boil down to two basic scenarios from what I understand: a.) the actual source of the bug could not be found, even though the developers thought they had nailed it down numerous times, or b.) the "fix" would have broken other parts of the game (e.g. there is a big pillar blocking the hallway, but it's holding up the roof...take it down, and the roof will cave in...leave it up and the hallway is blocked.)
Such things occur when dealing with 1,000,000+ lines of code from what I hear.

Furthermore, certain bugs are fixed, but the fixes are not retroactive, and that requires a new game to be started under version 1.32. Especially if players began their present playthrough in prior versions, then updated multiple times, it can leave the game "trapped" in places (though there are usually workarounds).
For anyone experiencing this particular bug, it does seem to crop up randomly, and I think it's of the "source can't be found" variety. Try to follow these steps to get by it:
1.) Reload to a point before the quest appears in your journal, and play through again.
2.) Do not fast travel after the quest begins (unless you need to change regions or something). Just Roach it everywhere.
3.) If you think something odd may have happened, immediately reload to your last save and try again. Better to lose 5 minutes now than have to go further back later.
4.) Ensure you are "following the road". Hit all check points, Witcher-sense hotspots, etc. and try to ensure you're doing them "in order". No shortcuts if the quest is giving you trouble.
5.) If all else fails, simply reload at the point you're stuck over and over again. On PC, this has managed to get me past -1 level enemies, non-responsive NPCs, and a couple of stuck chests, even though my record for consecutive reloads was over 20 in one instance.