Question: "couldn't be opened because you don't have permission to view it."
This is a re-emergence of a problem people were having in 2014 with Yosemite (see this link for that thread: Preview issues..."couldn’t be opened because you don’t have permission to view it.")
Now it's 2018 and I'm on my new 27" iMac running Sierra, and the denial of permissions to view image files is driving me crazy, including screen shots I had previously opened! In fact, yesterday any screen shots I made were openable immediately. Today they don't. Last week, an erratic pattern of images did and didn't open. Does anyone have any method for a permanent fix for this on OS 10.12 Sierra? Thanks heaps.
iMac, macOS Sierra (10.12.6)