Adding an ESXi/ESX host to vCenter Server fails
You see one of the following errors:
"The evaluation Mode license assigned to Host hostname has expired. Recommend updating the license"
"License not available to perform the operation. The Unlimited license for 'Host' (hostname) does not include 'vCenter agent for VMware host'. Upgrade the license."
The ESXi host system clock may show an incorrect date (for example, a date years in the past)
IPMI or BMC sensor logs on the physical server may show CMOS battery failure alerts