DIVA-GIS

Diva cli. and files
I have been traying to create bio predictions with past and present climates and DIVA doesnt allow me.
It tells me that is missing the Alt mask, and the goes when i try to create clim files.
Hope you can help.
My idea is to compare between present and past climates to make entropic predictions. How can i do this>?
Thanks
JOha