Exactly…you can’t manipulate the cropping feature…and the header turns into a black box. Same here.
you can also adjust the size of the minimum image for the custom image cropper in the functions.php file.
I am having similar problems with the header image cropper.
I am having difficulty using the custom header image cropping feature. The picture uploads, but I can’t crop it. When I save it the head is just a black box. I have tried different jpeg files of different sizes…but to no avail. It worked 3 months ago, but it hasn’t worked for me going on 2 weeks.