So I've had this issue for some time now and cannot seem to fix it. Every time I try to import my photos into lightroom this happens. I currently am using a MacBook Pro (Retina) with OS Sierra-10.12.3 and Lightroom 6.8. I had lightroom 5 and wasn't experiencing this problem but now nothing works. I also use a 1TB external hard drive in combination with these. Please help!
This is a corrupted file. The corruption is caused by a hardware malfunction somewhere. It could be a bad camera card, bad card reader, bad hard disk or bad memory. You need to try different camera cards, different transfer hardware, and if possible import on an entirely different computer to see if you can isolate the problem.