I recently upgraded our HP OneView deployment to 1.20.05. Following the upgrade, several rack-mount ProLiant systems showed up in the console as disabled. The strange thing is that the dashboard still showed active CPU, Power and Temperature stats on the Overview, so I knew the system was still communicating with OneView.
Having seen this before on a blade enclosure, I thought perhaps a refresh would solve the situation. Under Actions on an enclosure or server, you have a refresh command that goes out and repolls the iLO and tries to update everything. Unfortunately, when I attempted to refresh, OneView the system stayed in the disabled state.
A quick search online turned up a couple others who has experienced similar trouble and the resolution is a simple reboot of the HP OneView appliance. That seems to solve the situation and make everything go back to an OK status. My systems immediately came back in an OK state after reboot, but the user said he had to let it sit overnight, so mileage may vary.