I'm trying to crop an image, and although it shows an interface with a crop box, there doesn't seem to be a way to perform the action. I've tried hitting enter, clicking various aspects of the box, double clicking, right clicking, viewing different options but can't seem to find out how to make it work. Therefore, please improve the UI. Note: I'm a web developer and regularly use other image editing tools so generally and have done for around 20 years so generally regard myself as being fairly tech savvy, but I can't for the life of me figure this one out.