Autodesk has announced changes to their upgrade policy effective February 1, 2015. Basically, Autodesk will no longer offer the option to purchase upgrades after that date and you will need to purchase a new license unless you are on Subscription.
I've been advising my clients to ensure their software is on Subscription to receive future upgrades otherwise a more costly new license will need to be purchased
More information can be found in this Autodesk FAQ.
