When you first switch on a VNXE you have to go through the management network setup tasks, then you have to register the product to download and install the licence file for the software packs you have purchased with the hardware. This is where I hit a bit of a brick wall for a while with our first VNXE 3100. All I got when clicking the obtain licence button was a message on the EMC website saying the Product ID is not recognised. This happened if I type the product ID/ serial number in manually or let the system do it (as it does when you click obtain licence).
So I rang emc support and after a few days of waiting I finally got an answer from them. The support chappie said that it does that if the order company that is registered against the device shows and different to the name of the site so as we bought these from a reseller I guess they were registered under our company name on the order but the site was registered as the reseller.
Quite why this makes any sense I do not know but the support guy emailed the licence files to me and all is now running as it should.