Cubase 8.5.15 freeze and restart iMac!

I have really big problem days ago when I upgrade 32gb ram on my iMac:

iMac 2015 5k retina
i5 3.3 Ghz
32 GB ram 1600Mhz DDR3
AMD Radeon R9 M290 2048 MB
El Cptian 10.11.5

when I open any project after few sec or minute max. cubase freeze and restart iMac. Even blank project when I start playback its going freeze and restart comp. There s no spikes, latency or other issue, all seems normal but just freeze and restart every time…I suspected first on ram memory ofcoure, but this hapend only with my cubase. Logic x pro, after effect and other softwares works fine without problems. I m very desperate and have problem with deadlines, every piece of advice is more than welcome.