i think you've already found the issue. You cannot create a clone.. hence the restore fails.
aggregate xxx is not in aggr-list of Vserver xxx.
means you need to add the aggregate in the aggr list of the vserver
The aggr-list is a parameter that defines the list of aggregates assigned to a Vserver. This parameter is used only for aggregate-related volume provisioning operations. When a Vserver is created, it has an empty aggr-list, which means that the Vserver administrator cannot perform any volume provisioning operations. If the aggr-list of a Vserver is empty or does not contain the proper vserver list you cannot perform any provisioning operations that require an aggregate name. For example, volume create and flexclone create (the availability of these commands depends on the role assigned to the Vserver administrator). The operation is not disruptive, and with that basically you allow the clone operation required by the mount-sdsnapshot command
Current aggregate assignments can be viewed by running this command from the Cserver:
cserver::> vserver show -vserver verservername
Look for the line that shows List of Aggregates assigned.
Then you need to assign the aggregates specified in the error message to the vserver in question. (This might give a warning that the aggregate is in use with other vservers, this can be safely ignored. This command only allows the vserver in question the ability to perform operations such as FlexClone.)
>From the Cserver command line:
cserver::> vserver modify -vserver vservername -aggr-list aggrname
obviously if you prefer you can do that via onCommand GUI