Preview from pictures before and after import doesn't work
Hello Everyone
I got a big problem. I started Lightroom and when I want to import pictures the preview doesn't work and when I imported a folder it still doesn't work. But only in the library. In "Development" the picture shows correctly but under the picture where the other pictures of the folder should be shown, doesn't work it either.

Does anyone know what I have to do or can do?
Information to my computer:
- Windows 10
- Lightroom Version CC 2015.8
Thank you in advanced and best wishes
Dalia