License a Standalone ESX 9.0 Host with a Private License File (When the Trial Expired and vCenter Won’t Boot)
If you upgraded (or deployed) ESX/ESXi 9.0 in a lab and let the evaluation expire, you can end up in the classic chicken-and-egg situation: your vCenter is a VM, but you can’t power it on because the host is no longer licensed. With VCF / vSphere Foundation 9.0, licensing moved away from the old 25-character keys and into license files(normally handled through VCF Operations), which is great… until you don’t have VCF Ops up yet. (VMware Blogs) ...