After upgrading PVC for Windows Hardware Node to 4.6 it has the Not Available status in Parallels Business Automation - Standard.
Starting from PVC for Wondows 4.6, a Hardware Node should be registered with the node IP address. Since the node in question was upgraded it is still registered with the IP address of the Service Container.
Delete the node that was incorrectly registered from PBA-S: Top > Service Director > Virtuozzo Manager > Nodes > Hardware Node > General Settings > Delete.
Register it back with proper ip: Top > Service Director > Virtuozzo Manager > Nodes > New Node and specify protocol VZagent 4.6.