WordPress Media crop button greyed out

In WordPress Media it is possible to edit the images in some basic ways including cropping. To use the tool you must fist make a selection in the image by clicking and dragging across the image. The selection must be wider than the smallest image setting in WordPress. Otherwise the crop tool will stay greyed out. Once a large enough selection has been made the crop button becomes clickable. This is not always logical to the user who often try to click the crop button first.

Cropping images in WordPress