Today I've started playing Dawnguard (the spanish edition). I've decided to start with the dwarven forge quest "Perdido en los Eones" and EVERY new enemy (cahuros, Falmer Belico and Guardian de la forja) are INVISIBLE. You only know they're there if you use the "locate enemy" shout.
I've deleted the DLC and the title update. And then I've downloaded them again. The problem still remains. Is it a common problem or is it just me?