During a fresh install of NSX 6.4.0 I ran into a little issue that has a big impact because you cannot continue the initial configuration/installation of NSX. After the initial deployment of the NSX appliance, SSO and vCenter registration the next step is to add an NSX license. The problem is that your NSX serial key is not accepted.
The vSphere WebClient reports: The following serial keys are invalid.
On top of this the default vShield Endpoint license that should be available in the inventory (since NSX 6.2.3), is missing:
The problems lies in the fact that the user/service account that is used for the vCenter registration is not a member of the LicenseService.Administrator group. Since NSX 6.4.0 this membership is mandatory (as documented here). By default the firstname.lastname@example.org user is member of this group, but if you use a different user/service account things will go wrong.
Solution: add the user/service account to the LicenseService.Administrator group en re-register the vCenter server in NSX as documented here.
Now you should be able to add the NSX license to your environment. Also notice that the vShield Endpoint license is available as well:
Hope this was helpful!