iMac Graphics Update released with fix for issue viewing large JPEG images
Apple has released a graphics update for certain iMac desktop models intended to fix an issue that may cause the computer to become unresponsive. According to the release, iMac 2015 Update 1.o is intended to fix an issue for certain iMac owners running the latest version of OS X Yosemite.
If you’re using using OS X Yosemite v10.10.3 and one of the following iMac models, viewing certain very large JPEG (.jpg) images in the Finder or Preview can cause your iMac to briefly stop responding, display a black screen, and restart to a message that your computer restarted because of a problem.
The update is specifically available for the iMac (Retina 5K, 27-inch, Late 2014), iMac (21.5-inch, Late 2013), and iMac (27-inch, Late 2013) as a standalone download or a software update through the Mac App Store.