Sounds like the old one. Amazon always blacklists the defective unit if they don't want it back.
That Paperwhite will still function normally, BUT since you can't register it has not all functionality. DRMed books cannot be read, no access to cloud, no collections, no more spying of Amazon (???). The collections can be useable again if you use CM (I believe) even on non-registered Kindle. Sounds like a good unit to take out hiking, hunting, and traveling. If you break it, drop it into the water, get it stolen - no big loss.