Make sure that you are using the latest versions of vSpace Pro, and update from time to time, as there are some older versions of vSpace Pro that could eventually have been discontinued for registration as well.
As of the writing of this article, the current versions supported for registration are 11.3.7 or better and 12.4.0 or better, but this may change through time. Please, plan for reasonable upgrades as our versions change and improve.