I'm not sure if this counts as fatal, but i can't progress, so I'm assuming so?
So I talked to Aderyn and went to Weeping Hill, came back to level grind, and ended up joining the Ranger Guild then, and starting the first quest in that area. Apparently, doing that brought back the NPC that blocks off Weeping Hill, and talking to Aderyn again doesn't make her move again. So I'm stuck!
I can revert saves, I think? But just wanted to bring this to mind!
Thanks!
EDIT:
So I reverted the save to the point before I joined the Ranger's Guild, and the NPC was still there? So it's not the Ranger's Guild that does this, maybe it's leaving Celeste at all? I'm at a loss, I'm sorry!