This error means that, in our systems your email id is associated with a different customer record than the entitlement you tried registering against. Please contact NVIDIA Enterprise Support, as it appears that we may need to do some data adjustments to get this error fixed.
If you are a System Integrator contact or a Managed Services Provider contact who is trying to register for your customer’s entitlement, please note that you will need a unique email id for each customer in order to register for that customer’s entitlement.