This means there are no more security patches, bug fixes, or official support from VMware (now Broadcom). Running this in a production environment poses security risks. If at all possible, you should look into upgrading your vCenter and ESXi hosts to a modern version (7.x or 8.x).
Alex needed the immediately to manage an old ESXi host. But the journey wasn't as simple as a modern app store click. The Search for the Lost Installer