Tp scrolls

Why does it sometimes say "You can not telleport during a questline" when I try telleporting with scrolls?
If I /class its fixed but I still wanna know why this happens

 

Well you can't tp when in a questline...

 

I assume it doesn't allow you to teleport to prevent you from doing stages of a quest too quickly (i.e. obtaining the Siegfried Fan items from Llevigar and Cinfras), but I'm not really sure.

 

but it says that when there is no quest active

 

It just happens sometimes. It's a bug, but I don't know how or why it happens. I guess the game just flags you as being in a questline sometimes? I've noticed either finishing certain questline quests or doing certain raids seems to cause this to happen, but other than that, no idea.