My Motif XS Rack was working perfectly with my studio set up for about 2 Years, no upgrades to the set up that could have caused the issues.

Motif XS Rack is crashing MAC Pro - 12 core 64 ram, mid 2012 model with OS sierra and CUBASE pro 8.50.

Running Motif firewire, and Integra 7 via usb as an aggregated device. Motif started crackling in occasion, then the sound started to drop in pitch as if the digital frequency was being changed, then eventually started to drive the cpu to overload, then started crashing the mac.

When I disconnected the firewire cable, and used the Motif via usb, all was working normal.

I re installed the drivers for all the hardware I am running, updated all the VST"s and re installed CUBASE, and updated Sierra OS, I connected the Motif via firewire, the MAC did not shut down, but was working very sluggish, I opened CUBASE and no shut down, when all was running , I stroke a key and the sound lasted for a half a second and did not respond to my playing, no sound.

Has anyone encountered this issue, and found a fix for it?

Any suggestions?