NetApp file server 'server-name' at Data ONTAP version 'version.modification.submodification' is not supported for performing incremental backups using snapshot difference.
Incremental backup using Snapshot difference requires Data ONTAP V7.3 or later. However, if you are upgrading from Data ONTAP V7.3.3 or later to V8.0, you will lose snapshot difference support for unicode file names. Upgrade to Data ONTAP V8.1 or later.
Processing stops.
Upgrade the file server to a supported level of Data ONTAP, then retry the operation.