Staff of Starlight - Forcefield Bug?

[kabouki]

I assume you talked to three mages on the forcefield because only after that you're able to deal with the altars. I guess you've done that because prior to this you're unable to battle the guardians of the altars. If you've done this and the forcefield is still up you should update your game with the latest patch, reload a game at least before you entered Arlania for the first time and try again