I am using Aeon 2 and the Windows beta for Scrivener 3.
I think the problem is a bug in beta 14 in which when you close the program, it actually crashes and the user.lock folder is not deleted. If I remember rightly, this happens if you are in "Scrivenings" mode when you close the program or even perhaps in single document editor mode. I think I read that the work-around for the moment is to switch to Corkboard or Outline mode before you close Scrivener. Hope that helps.
Thank you. I will try this. Fooling around with it, I set up the first four scenes in Scrivener 2 and the syncing worked. I figured it had to be some kind of bug. At least I know it will work. Was concerned that I'd wasted my money. Thanks again.
With the launch of Beta 15, the bug may have been squashed, but trying it—as I'm on a Mac, I run the Windows betas using Crossover—closing the project before shutting down Scrivener may be another solution.
@bundie, I see I forgot to say, if you still haven't been able to open your Scrivener project, using Explorer or whatever it's called, look in projectname.scriv > Files; you should see a "user.lock" file. As long as you're sure you haven't got the project open on another machine, it will be safe to delete that, after which it will open normally. If you're really nervous about doing such a thing, make a copy of the project and try first on that. :)