Upgrade CRM2015 at CRM2016

Hi,

I try to upgrade from CRM2015 to CRM2016 but I have this error when I try to import the organization:

This organization cannot be upgraded. You can only upgrade organizations that have a version of CRM that is no earlier than Microsoft Dynamics CRM 2015.

The version of CRM2015 is: 7.0.0.3543 (DB: 7.0.0.3027)

The version of CRM2016 is: 8.0.1.79 (DB:8.0.1.79)

Do you have any idea?

Thanks

A.G.