Premiere Pro CC 2017 - (Running on Yosemite 10.10.5) - Crashes on saves

Hello community!

I'm running an iMac, (Stats: Processor: 3.5GHz Intel Core i7, RAM: 32GB 1600 MHz, Graphics: NVIDIA GeForce BTX 780M 4096MB).

I'm a video editor. I'm starting a new project, and as we all know, it's best to start and finish new projects in whichever version of the software you want to be in the whole time. So I updated my CC Suite to 2017! Yay! New stuff!

The footage is RED Raw 6K footage from the Dragon, big files, but nothing we shouldn't be able to handle. Running it through the 21TB G-Speed Studio XL RAID-formatted drive, on a Thunderbolt connection. Currently, there's about 3TB of footage being accessed total.

SO. I start a new project. Import all the RED files the right way, without the weird extended takes thing Red does. Audio: It's a musical, so we have like four audio clips per video clip, so I'm sync-ing files by just creating new sequences for each. NBD, fine.

I go to save. Fine. Fine. Fine. Then... Blam, out of nowhere, the whole computer just shuts down, goes black. WHAT!?

Restart. Cry about my poor RAID getting jerked around. Plug her back in. Run Premiere. Get it going again. Save once, fine. Save again, BLAM AGAIN. Computer goes dark.

Called Apple for a half hour, then talked to three different people at Adobe, who told me to save the project locally (which sort of worked, but is not a project-long solution, because I don't want to lose my project file), and one person had me change the subfolders so that Premiere had to reset my preferences for some reason, and the other person told me it was an problem with the RAID or the Mac, not the Adobe software. OKayyyyyy, so I call Apple. Since it's not their software, they're very nice, but can't help much besides helping me run a diagnostic on the computer and the RAID. All fine.

SO yeah, anyone else having this problem? I've decided to revert to CC 2015.3 for Premiere, After Effects, Media Encoder, and possibly a few others, for this project. I'm officially one day behind, trying to solve all this, so I'm just gonna use the previous version. But if anyone out there has run into the same thing, I'd love to hear your work-around.

Thanks!