The ontological paradox is a really fun thing to mess with. And despite it’s name, it’s not a cause-and-effect paradox where something happening causes itself not to happen. The “Paradox” it refers to is the one where the information appears to already exist, rather than being created at some point.
 
So where did Twilight get the information about the time travel spell from? Answer: easy, she got it from herself. The loop is closed and stable, it doesn’t matter that it doesn’t have a start. :)

Cause: Twilight learns where scrolls are from someone.  
Effect: Twilight informs someone where the scrolls are.  
Makes sense to me.

I already have a theory that solves this.

Twilight! What have you done?! The future will be changed!

The information does and has to have an origin for the time loop to begin. It’s just that how past Twilight came of the knowledge of the time scroll changed during the multiple time loops.

TimeSplitter rules

Ontological Paradoxes really fuck shit up. And make my mind hurt.

The information has a beginning, but no origin. You know what’s great?  
THAT HAPPENS IN REAL LIFE.

FEY RUNE YOU NEED TO FIX THAT SHIT UP

TH3 UN1V3RS3 34TS P4R4DOX3S FOR BR34KF4ST

Except that the information has no origin. Twilight never learns of it from a non-Twilight source.

not a paradox more of a loop it happened because it happened