Hopefully I get some help on this matter :(
So, I finished the Soulstone Quest so that I could get myself a nifty soulstone. However, even though I received the soulstone ticket, which then I traded into an actual soulstone, when I went to equip it, the system told me that the item cannot be used. To my surprise, when I went to check the soulstone socket on my character equipment, the soulstone socket had in between brackets "locked".
So I was wondering if this is a bug or just a mess up on my part, and if so, how can I unmess it, seeing as soulstones are quite important to one's progress in-game!
And just in case, yes, I did finish the whole quest line of soulstones!