I have a serious problem while cropping images using your plugin... It's all fine when I'm cropping the default sizes, e.g. for thumbnail and medium cropping works just fine but when it comes to custom sizes the plugin doesn't work at all. I get "Can not update attachment data" error and not only this size isn't cropped properly but also the other already set crops reset to default.
There's also an error while cropping the large size. In this case error is "Invalid target". The cropping isn't done for that size and the same as before other sizes set back to default cropping.
Can you help with that problem?