I'm trying to update the Cluster Functional Level of a two-node Hyper-V cluster where the original Win 2012 R2 nodes have been replaced with newer Win 2016 nodes. The new nodes went in without issues, and the old nodes were removed without problems, but I can't raise the Cluster Functional Level from 8 to 9:
PS C:\Users\T-DLA01> Update-ClusterFunctionalLevel
Updating the functional level for cluster HVSAN01.
Warning: You cannot undo this operation. Do you want to continue?
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): A
Update-ClusterFunctionalLevel : Updating the cluster functional level failed.
The cluster did not successfully complete the version upgrade
At line:1 char:1
+ CategoryInfo : NotSpecified: (:) [Update-ClusterFunctionalLevel], ClusterCmdletException
+ FullyQualifiedErrorId : Update-ClusterFunctionalLevel,Microsoft.FailoverClusters.PowerShell.UpdateClusterFunctio
I've checked everything I can think to check, including ensuring all required cluster resources are present.
This is the test bed for a much larger cluster upgrade scheduled for early next year.
TIA for any assistance you may be able to give.