I have used lightroom for ~2 years and have lightroom 5.5 installed on a PC. Yesterday evening I uploaded a new set of photos which I cataloged and rated as usual. After that when I switched to the develop module trouble began. First thing was when using the crop tool the picture would disappear and only reappear once I closed the tool. Then exposure and White balance changes would change the histogram but not the appearance of the photo. Finally clipping was also not appearing on the picture. I first reuploaded the photos. No effect. Then I reinstalled lightroom. No effect. Help please!
Just thinking out of the box, since I have no idea why this may have happened. Have you tried clicking on the rest button within the boundaries of the crop tool controls?