Continuing the discussion from CDKey Lookup Changes:
In Rhino 6, license validation will be more strict in some ways, but less strict in others.
A user validating a Rhino 6 Upgrade license will be required to enter a previous version license. That previous version license must have a complete upgrade chain back to Rhino 4.
Once upgraded, Rhino 5 licenses are no longer valid for validation. So new installations of R50s that upgraded to R60U will not be allowed to validate. We may change this policy if we find lots of users have legitimate reasons to need R50.
Future validations of R60U licenses that have already been associated with previous versions no longer require a previous version license key to be entered. For all intents and purposes, the R60U becomes a full version license assigned to the email address used to validate. The intent is to make it so our customers don’t need to keep detailed records linking their licenses together. In fact, they could just throw away their old licenses after validating.
What do you think?