Latest Reaper 64bit No output iMac RME

[ianpq]

Hello - If I upgrade to the latest Reaper 64 bit version (5.965) I loose the main output on my RME Babyface to outputs 1&2. I thought this was a MAC OS problem and have both Yosemite and Sierra and it happens only when using the more recent 64 bit versions. It's no problem, I just go back to an earlier version of Reaper(5.25 works Ok). This doesn't happen on the 32 bit version of Reaper. I am using an iMac intel core i3 which is apparently 64bit. I'm not stuck, all is fine and I can work around, I just wondered if anyone has any thoughts on whats going on?

Thanks