iMac 5K crashes when selecting large jpegs
I have a new iMac 5k, and I've noticed a very troubling issue. It's hard to figure out where it is coming from or what is causing it, so I'm hoping there'll be someone who has been through this before and knows what to do.
I export images from Lightroom or Capture One, simple full size jpegs at 100%, with metadata to my desktop or other folders. If the image is over a certain size, and I click on an individual image, within a second the entire computer has crashed and is restarting. If I select several of the images, everything is fine, it's when I click on one. I don't click to open the image, just select it. I've imported RAW images without issue, selected them, previewed them with no problems at all. Only exported images.
As a test, I've transferred the jpegs that crash the iMac to my laptop (by selecting multiple and moving via airdrop) and open them without any issue, so I don't think it's Lightroom or Capture One. I'm trying to figure out if this is a software or hardware issue. I think it might be a corrupted file somewhere that reads the metadata and previews the image with a thumbnail, but haven't found anything useful googling yet.
Any ideas? I'm happy to provide whatever info/screenshots about the issue to help.
iMac (Retina 5K, 27-inch, Late 2014), OS X Yosemite (10.10.3)