I've been using affinity photo for some time now and have had no problems whatsoever when editing photos taken on my Nikon D7500. I have recently upgraded my camera to a Nikon D850 full frame (45megapixel) which produces much larger raw files (45-80mb), but have also been successfully editing photos for the last 2 weeks, which is the time that I've had the new camera. Tonight whilst processing a photo, the affinity photo app completely crashed without warning. The screen simply went black and I had to turn off and restart the computer. Subsequently, from then on, I was able to open the program itself, but each time I tried to open a photo in the app for editing, it has completely crashed. I have followed other advice and uninstalled/reinstalled the affinity app. I have used ^(ctrl) to reset all of the app's data to the default settings, but it still keeps crashing. The program will open ok, but as soon as I try to load a photo in order to edit it (from any source) the app simply crashes. It completely locks my MacBook and then shuts it down. If I'm lucky, it will restart on it's own. I have tried loading photos using several photo viewer apps, such as view nx (Nikon's own software) or iOS preview, but the result is the same - the app crashes. All my other photo apps appear to be working fine and I can view and edit photos using any number of other programs, such as Photoshop Elements or Capture Nx, so I'm happy it's not a graphics issue. I am running iOS High Sierra on a 2011 MacBook Pro with 32gb ram, a 240gb ssd (used to run the operating system) and a 2tb hard drive (used for storage and about a quarter full). I am also running the latest version of Affinity photo 1.7.1. The only other thing maybe worth a mention is I downloaded a free brush pack recently. Any ideas?