I was not able to crop images, too. The area where the cropping should show was just blank, instead I got the error message: “Image crop area preview. Requires mouse interaction.”
This was on a freshly installed WordPress on a shared hosting provider. I also was at the theme image selector, as this was the first thing to touch.
Now there was also other suspicous things:
- the media image library showed no thumbnails.
- When activating developer mode in the browser, I noticed some resources of WordPress could not load.
Solution: the access rights to /wp-content were broken, Apache was no longer able to read the files that wordpress had written. In my case, recursively changing the access rights of wp-content to rwxr-x— did solve it.
