Not sure if you've finished implementing the wights quest - I completed the bandits quest in my game and wasn't able to start the wights quest, now when I load my game I get this. You put an "," before the if on line 40992.
error = "Lua Error: /engine/Entity.lua

/data/general/npcs/all.lua:40992: unexpected symbol near 'if'\
At [C]:-1 \
At [C]:-1 error\
At /engine/Entity.lua:1147 loadList\
At /engine/Entity.lua:1186 load\
At /data/zones/town-bree/npcs.lua:21 f\
At /engine/Entity.lua:1193 loadList\
At /engine/Zone.lua:166 loadBaseLists\
At /mod/class/Zone.lua:48 loadBaseLists\
At /engine/Zone.lua:732 loaded\
At /engine/Savefile.lua:552 delay\
At /engine/Module.lua:1050 instanciate\
At /engine/utils.lua:2221 showMainMenu\
At /engine/init.lua:165 \
At [C]:-1 dofile\
At /loader/init.lua:217 "
Have you finished creating the bree_wights quest? What it did in my game (which I hadn't reloaded up until now) was replace the entrance to the barrow downs with a quest entrance, and then when I entered there was nothing, not even look worked. Luckily I hadn't saved recently and I terminated the game process so I still had my game before I triggered the quest.
If the quest is level 30, maybe there should be an additional warning before you accept it? I'm level 15 Yeek Sorceror, but you don't need to be so high level to have completed the Bandits quest and ask for a new one. I'm guessing that you haven't fully implemented the quest yet. But I don't think the player character should be able to casually replace the Barrowdowns entrance with the level 30 quest entrance, especially for melee classes. Is it just meant to trigger on level 30 of the Barrowdowns (if there is such thing)?
I am now on L5 of the Barrowdowns, but the princess quest didn't create correctly, so there may not be an exit to the next level (since the princess quest blocks all other down exits). Is it possible for you to edit the savegame so there is an exit, if the princess setup got to the point of blocking exit creation?
error = "Lua Error: /engine/Chat.lua

attempt to index field 'npc' (a nil value)\
At [C]:-1 __index\
At /engine/Chat.lua:100 invoke\
At /data/quests/princess.lua:137 \
At [string \"return function(l, self, data) local ok=false...\"]:1 triggerHook\
At /mod/class/Game.lua:480 changeLevel\
At /mod/class/Game.lua:974 \
At /engine/KeyBind.lua:242 "
Also, an error when I tried to use a skill (spell I think):
error = "Lua Error: /engine/interface/ActorTalents.lua:279: /engine/interface/ActorTalents.lua:256: /engine/interface/ActorTalents.lua:150: /engine/interface/ActorTemporaryEffects.lua:113: attempt to index local 'ed' (a nil value)\
stack traceback:\
\9/engine/interface/ActorTemporaryEffects.lua:113: in function 'setEffect'\
\9/data/talents/spell/divination.lua:118: in function </data/talents/spell/divination.lua:112>\
\9[C]: in function 'xpcall'\
\9/engine/interface/ActorTalents.lua:147: in function </engine/interface/ActorTalents.lua:140>\
At [C]:-1 \
At [C]:-1 error\
At /engine/interface/ActorTalents.lua:279 useTalent\
At /mod/class/Player.lua:640 useTalent\
At /engine/interface/PlayerHotkeys.lua:170 \
At /engine/interface/PlayerHotkeys.lua:162 activateHotkey\
At /mod/class/HotkeysIconsDisplay.lua:178 onMouse\
At /mod/class/Game.lua:1208 fct\
At /engine/Mouse.lua:58 "