Pro Tools 12 and 11 Crash on El Capitan

[Don Peterson 56]

Does anyone have PT 12 running on an IMAC w/EL Capitan 10.11.3? Will 12.4 run on Yosemite?
PT12 crashes like crazy. Any command can trigger the freeze. The Imac Screen and control freezes whilst the music plays on. Only way to stop is a pwr button hold reboot. As I continued to hunt for the problem, it got worse. Before it would crash, error message CPU overload/raise edit buffer. This would happen with a couple tracks and plugins. The PT processor monitor said 2% on 4 cores. Bailed on 12 and loaded PT11. Preliminary use (just like 12) has ok results, but Imac meter shows processor using 40-60% (while PT monitor still says 2%) on 16 track session with as many plugins. After a few runs now PT 11 is intermittently freezing too. F3 unlocks it for now. After closing session, Imac won't shut down. Power button hold is only way to shut down.
Upgraded Pro Tools from Sweetwater. I have 10, 11,12. Purchased an IMAC Nov 2015. About says Late 2014 3.5 1TB Fusion, upgraded Ram 24g
Apollo 8 interface, 2nd display Apple all thunderbolt connected. El Capitan 10.11.3

[clutch]

The fusion drives are known to be problematic with PT. Are you using an external drive to run your session from?
I'm running 12.4 on El Capitan on a MacPro 5,1 currently and having a few beachballs now and then when running over ~450 voices, but nothing like you're describing.

[Don Peterson 56]

Thanks Clutch. I should probably dump the Imac for a Mac Pro. I'm going to try Studio One 3 first.

[Don Peterson 56]

System requirements say Mountain Lion 10.8.5

[JFreak]

http://avid.force.com/pkb/articles/e...tibility-Chart