Reinstall Mac OS Sierra?
I recently upgraded to High Sierra. My most important application, Bias' Peak Pro 6, no longer works properly. I have a Mac Pro (mid-2010) with four hard drives installed. I want to install Sierra on one of the disks, but can't find a Sierra installer in the App Store. Can someone help, please?
Mac Pro, macOS Sierra (10.12.6), MacPro 5,1, with 2.8GHz quad-core