Hello and thanks a lot for your feedback! I am very glad you like Slate 🙂
It seems that there went something wrong when you re-imported the package in the project. Did you do so from the asset store?
Please try deleting the Slate folder completely from your project and re-import it anew from the asset store once again.
Please let me know if everything works correctly after re-import.
Thanks again!
Gavalakis
