"Flora" Error on Runtime

[stevanas]

This error popped up out of nowhere and I cant seem to remove it. Tried deleteing Library etc. Not sure whats wrong? I has no issue on a smaller terrain. Im using on of the presets. Thank you!

 

https://gyazo.com/e06d844bf4dab4af05dc2d6bbf4b5df1

[Bryan]

One of the detail object's index is trying to reference a value outside what is currently on the terrain.
I.e. if the type is detail, and we only have 1 detail object, then an index of 1 or 2 would out of range, whilst an index of 0 would match