🚀 go-pugleaf

I am playing Gothic 1 as an Old Camp guard, and I have never been able to
use a scroll. I first tried a Transform into Meatbug, and now am trying the
Orcish Teleport scroll. Both scrolls require only 5 mana, and I have much
more than that- however, each time I try to use either of the scrolls (in
their appropriate locations), the following happens:

1. The game makes the sound and lighting effects which usually accompany a
successful spell (as in Gothic 2).
2. My mana is not depleted.
3. The scroll is still there.
4. The scroll doesn't work, and there are no on-screen warnings explaining
why I can't use it.

Am I supposed to do something special in Gothic 1 before I can use a scroll?
I've noticed in my character stats screen it says "Magic: no." Is this
significant? The manual doesn't describe this screen at all.

I fear I won't be able to finish the game unless I figure this out.

Thanks.