Very strange thing happening after import.
My usual import flow is to use dropbox's image capture to store photos from my phone and my SLR into a folder. Then once a week or so I import this folder into LR.
I have been doing this for more than a year without any issues.
Since the last big update (I think) when I perform this import I see my photos, I click on one in the timeline, then after about five seconds about 80% of the image goes black, just a bar of the image appears along the top.
This then proceeds to happen to every file in the import.
If I import direct from the camera, THIS DOES NOT HAPPEN. so, clearly I will do that for the time being, but just curious if anyone might know why this is happening. Here is a screen capture.
Back in 5.7; I had a data corruption issue with previews. It was tied to importing from one specific folder (an archive folder I was dropping images into as I de-duplicated files). The solution was to exit Lr, delete the previews and rebuild.