The host is not properly registered to vCenter.
FIPS might be enabled on the host.
When customers upgrade something in the VMware environment, the host might be rebooted in the process.
VRA on the host might not be powered on after the host reboot.
vCenter might show a error when powering on the VRA: The operation is not allowed in the current state of the host
--Unregister the host from vCenter and register the host again;
--For disabling FIPS:
Go to Administrative Tools > Local Security Policy > Local Policies > Security Options > System cryptography: Use FIPS compliant algorithms for encryption, hashing, and signing
Switch the flag to disabled.