Nodes error Overall hardware status unknown

Hi

Since we upgrade to version 6.0.0 some nodes appears in the "nodes with problems" table with the status "Overall Hardware Status 'Overall Hardware Status' has state: Unknown. " The check of the hardware status can not be disabled. How can i get the hardware status for this devices or disable the check? the hardware are routers junipier, switches Cisco and f5 bigIP load balancer

Thanks