Hi all. My first post. I'm just editing a job and have had these random colours/dots/lines appearing on my images in the Develop module. If I look at the image in Library, it's fine. I restarted LR and all was going okay then it's happened again. Please help? Kate
Hi Kate. By any chance, are you using Smart Previews? If so, smart Previews have a problem rendering some files. Adobe didn't really explain to me why but in files with high ISO/ low image data from underexposure you'd find this while using Smart Previews. I'd see if I can dig out the post(if it's the same thing). When you export, the picture would be fine btw.
Are you using an custom color/monitor profiles? If so, try eliminating them to see if the issue goes away. The other suspect is a bad graphics card. You could try disabling "Use Graphics Processor" under Preferences > Performance.