What do you mean “results in a broken link”? The image was not uploaded at all? i.e. you can’t see the image you would like to crop on screen?
1 – default max file upload size is 2MB
2 – check if GD library is installed.
3 – can you upload images via Page/Post Write Panel and do they show up after you publish the page/post?
4 – change theme to bp-default theme and see if the upload works