Darn.  I haven't seen it yet it .952.

But it has been reported  before in older versions

.95     https://forums.elementalgame.com/429719

.915   https://forums.elementalgame.com/427669

and    https://forums.elementalgame.com/427105

Best guess is it can randomly give you quests but that most of the quests can't be repeated, so the more scrolls you buy the worse it gets.  A few can be repeated, so the dud rate never gets to 100%.  I think the random selection is when you buy it, not when you try to use it, so save before you buy.

In my current campaign I've had the Assassin's Blade quest twice, and no duds yet, so I was getting hopeful.   Silly me.