It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

So I'm trying to fight a noonwraith. It's said you gotta use Yrden to trap her. But my sign doesn't appear on the ground at all. It appeared once and then stopped. I don't know why. I just use it now and nothing happens.