I attempted searching this message on the Support site (https://support.netapp.com):
The partner node details weren't found for the nodes with the following serial numbers
It returned nothing. As a ditch effort, I plugged it into Google and reached this KB:
https://kb.netapp.com/onprem/ontap/dm/System_Manager/System_Manager_reports_The_partner_node_details_were_not_found_for_the_node
It seems that the separate words were cobined in to the contraction and the search engine on the support site misses that...