ERROR : Hair asset descriptor is not valid. Failed to open hair file("hairside.apx")

Hey i solved my first Problem, now i have when im Export this Error " Hair asset descriptor is not valid.
Failed to open hair file(“hairside.apx”)" , Its Exportet from Maya 2018 . any Ideas?

Thanks!

Oh and Its just this error " Hair asset descriptor is not valid.
SO no “No Growth Mesh” Error