To reset CNO password:
- Open Failover Cluster console.
- In the left pane click Cluster Name
- In the "Cluster Core Resources" section select server name resource, right-click it and select Take Offline. VMs will not stop.
- The on server name resource choose More Actions -> Repair, this will reset CNO password
- Bring online server name resource.
Live Migration should work again now.
While troubleshooting the problem you can generate cluster log with Get-ClusterLog Powershell command, which will generate a text based log file C:\Windows\Cluster\Reports\cluster.log.
During live migration we would see there that CLUSTERNAME$ account cannot authentication because of wrong password.