Our most recent macOS test viewers will run on macOS 10.12 (Sierra). For the SL Viewers that would be version 220.127.116.11869 and newer. For the OS viewers that would be 18.104.22.168582 and newer.
Our macOS developer, Gavin Hird, reports that the older versions all experience various performance issues and crashes when run on Sierra.
OS test viewers download link is https://sourceforge.net/projects/kokua.team-purple.p/files/Kokua-OS/.
SL test viewers download link is https://sourceforge.net/projects/kokua.team-purple.p/files/Kokua-SL/.
Please report any issues using our ticket system at https://sourceforge.net/p/team-purple/kokua/tickets/.