In one of the favor quest for Lady Arabelle, the task is to find what happened to scouts 'near the shoulshriven tower in Rivenspire', related to a story with Lord Rihard at-Tura and his brother (at least in the French version of the game, it is said 'Rivenspire').
Firstly, the shoulshriven tower is in Stormhaven, near the at-Tura Estate, not in Rivenspire. You can see a circle marking the location of the quest on the Stormhaven map, near the wayshrine.
Then, as soon as you leave Glenumbria and the favor quest panel to Stormhaven using a wayshrine (or going to anywhere else outside Glenumbria), the quest disappears from the list of active quests (J key), and the daily quest is reinitialized at the favor panel.
Nevertheless, if you go to the shoulshriven tower, you find the dead bodies of the scouts along the way to the tower, and in the tower, you find the body of the scout captain. Near him, there is a shining book, I suppose it is the book to read to discover what happened to the scouts and validate the quest. But you can't click the book with the E key. The book is shining light, but can't be clicked while the quest is no more active when you arrive there.

Is is blocking for progress in the success 'do all favors for lady Arabelle'.

I posted a bug report in game.