I'm in Ch. 5 at the Old Manor. Up until this point, I've had no trouble at all casting any sign. But now I can't cast any at all. By that I mean that when I right-click, nothing happens most of the time. Every now and then, I'm able to cast, but not consistently. Endurance is full. No effects or potions that would block casting (as far as I know).

I found one old (2011) post describing the same problem in the same location but no real solution. Any ideas?