Just so you know, there is a bug which seemingly occurs randomly. It happened to me in the Endless paths under Caed Nua, when I googled it it happened to quite a lot of people there but also in a lot of other locations.
What happens is your ranger companion just disappears and it's portrait is replaced by a white circle, reloading save doesn't work and you also can't leave the area because you need the whole of the party to venture forth.
Luckily I had another save about 10 minutes back, so if I was you I would keep at least 2 saves until it is fixed.
Edit: Yeah stay away from the endless paths, happened to me again there. Also, restarting client sometimes fixes it.