Has anyone been able to add a new quest to the original game world ?
I copied this file : http://www.grimdawn.com/forums/showpost.php?p=379718&postcount=6
Thancopied all the ressources from the main game inside the source folder and added my new quest into the woeld, rebuild all path, maps and save all.
While building inside the Asset Manager, I had an error, but the build finished :
Cannot open[…]source/levels/Region0A001.lvl for reading
But the game doesn’t see the quest.
Bump. I’m curious about this too. Without a reply I may list it as an unsolved question.
not sure what you mean by “game doesnt see the quest” and Im no expert when it comes to making quest because I have made a total of ONE quest so far 
But it did need a conversation to get in game. If you are talking about you cant get the quest in game than that could be it, if there is another way of checking if a quest has been added to the world… I have no clue. Except try again and make sure the files are not set to “read-only”, Im doing the whole save thing again for the main campaign right now, no idea if its case-sensetive but if it is for me its in \Levels.
But I also come with a workaround for adding quests to the main campaign. Use an old quest, if you want to make it repeatable add tasks after that quest is completed and use the conversation to start at that task you call your own. Not perfect but its modding, so workarounds may be the best we get 
Hi Warebare, thanks for your info but I already did all of this, it is working if I modify an existing quest or if I create a new world.The quest is working and we can see it in this case.
The issue is to keep all the original quest files and add new quest to the world (new .qst file name).
Fot this we need to add the quest to the world (.wrl) and build it but for now we don’t have all the original game levels (.lvl) so it is not possible to recompile the main game world.At least that what I understand.