If you power on a virtual machine with Fault Tolerance enabled and no compatible hosts are available for its Secondary VM, you might receive an error message.
You might encounter the following error message:
Secondary VM could not be powered on as there are no compatible hosts that can accommodate it.
This can occur for a variety of reasons including that there are no other hosts in the cluster, there are no other hosts with HV enabled, data stores are inaccessible, there is no available capacity, or hosts are in maintenance mode.
If there are insufficient hosts, add more hosts to the cluster. If there are hosts in the cluster, ensure they support HV and that HV is enabled. The process for enabling HV varies among BIOSes. See the documentation for your hosts' BIOSes for details on how to enable HV. Check that hosts have sufficient capacity and that they are not in maintenance mode.