Late entry into this issue: I've been running Snow Leopard and Aperture 3.4.5 as long as possible, but wanted to upgrade before I missed the boat entirely and forever once 10.12 is released. All the posts here were very useful, and I pasted the URL into an online chat at the general support area. That led to "you need to speak to someone" and they called me immediately (with only a couple minutes on hold.) The first person was really appreciative of the homework, and based on this discussion put me straight through to Enterprise Support. The lady there understood the issue and knew the fix was elsewhere, checked and then transferred me to the Pro App Support. She waited on line to introduce me to that rep, who knew exactly what we needed: a support ID from the box. So far, about 8 minutes on the phone after the initial chat.
After multiple interstate moves, the first box I found was back from v1.5. He said it could be made to work, but it would help to have the support # from v3.n. He put me on hold to get a Pro App Support Supervisor. By the time he came on line (again introduced by the previous rep), I had found my v3.0 box and read him the support ID. He then said all would be good and that I would be getting a redemption code somewhere between a couple hours and a couple of days, depending on level of business on their end. He then gave specific instructions on how to use the redemption code to get Aperture 3.6 listed in my purchases and how that would even let me move it to different machine. He waited on line until I had his email with his direct contact information, and then rang off. 17 minutes later, I had the code and it worked as advertised.
Many thanks to those who have shared their experiences here and made this easier. Many thanks to the various staff at Apple who made this work without any question or grumbling about supporting a program that was EOL quite some time ago. Still, it's a loss not to have this software still under development.
