Cropping does not work locally

I am currently creating a web page where I am cropping images. On the server at Strato everything runs perfectly. Only locally, be it xampp ,mamp or the php server, the images do not crop.
What could be the reason for this?


Are you using the default gd driver (i.e. no thumbdriver set in your config) or im for ImageMagick?

If defaultGD library, should be present with MAMP.