I have a fully working hackintosh. And i see how Reaper crashes all time. It happens suddenly when I'm working. And it happens when i finished and Close Reaper. I have two configurations of Hack (desktop on El Capitan and laptop on Mavericks) and it happens on both. I'm understand that it cause of plugins, but it happens more often than I would expect. So different plugins may cause it. Maybe because overall stability is not enough yet? And it better on Win, that we hear from Win users.
Here is a log file for example.