For any software that has anything resembling DRM, which is a vast majority of software, once the company goes out of business, there’s no way to activate it. (Unless they address the conundrum before taking down the activation servers, of course.)

This isn’t really a downside of the licensing scheme itself, though. If it was DRM free and on the honor system, it would not have this drawback.

Of course, it’s currently unclear if a software development tool can remain relevant for many years after it is effectively unmaintained, so maybe this isn’t that interesting of a question.