Migration from ZCP 7.1 or earlier to Kopano Core 8.5 or later is no longer directly possible.
Starting with Kopano Core 8.5 it is no longer possible to directly to upgrade from ZCP 7.1 or earlier, as the database upgrade functionality for old Zarafa versions has been removed, see JIRA tickets KC-859 and KC-839.
From ZCP 7.2 it is still possible to directly upgrade to Kopano Core 8.5 or later.
How to migrate to Kopano Core 8.5 from an ZCP 7.1 or older.
To upgrade such an installation to Kopano Core 8.5, it is required upgrade to the Kopano Core 18.104.22.168 first, afterwards you can upgrade to the latest Kopano Core release, alternatively it is also possible to upgrade to ZCP 7.2 first.
Depending on version of your ZCP installation the database upgrade can take some time, take this in account when planning the migration.
Migrating from ZCP 6.40 or earlier.
Please contact support for more information.