The Carrara 8.5 “Beta” doesn’t come with all the standard content which you would normally get with the full version of Carrara, this is mainly to keep the download small
The leaves are needed for Carrara’s plants,. so they need to be with the main program.
You Don’t need to have the “carrara native content” installed, to be able to test the beta.
But,.. If you want to,. and you already own a previous version of Carrara,. then you can install your “Carrara Native Content” again, into the beta folders.
Hope it helps