Are you trying to license vCenter Server (VC) or vCenter Operations Manager (VCOps) ?
Those are two separate products.
- vCenter Server (VC) is the VMware core infrastructure management tool
- vCenter Operations Manager (VCOps) is for monitoring and troubleshooting the virtual environment (and also physical).
This is the community forum for vCenter Operations Manager (VCOps), but I am starting to think that you have problems with registering vCenter Server.
Alex D.