I have a new problem. Newly imported picture sometimes turns diagonal in lightroom. It's very strange. Most pictures look wel and now and then one turns diagonal. How is this possible. I cannot use the undo button because I did not do anything with the picture.
Sounds like you apply Automatic Upright on import, to straighten your horizons. That works well most of the time, but sometimes Lightroom sees some diagonal lines and thinks these lines must be horizontal or vertical. That can happen if your image shows beams of sunlight, for example. The result is very odd rotations.