I'm currently working on a website and I'm using two plugins :
Post thumbnail editor
Simple Image Size
I added some image size to my functions.php file and I forced them to be inserted into posts. With Post thumbnail editor I can crop and make my thumbnail looks different for each size.
My trouble is that somehow the .jpg file I'm uploading can't be modified with the plugin. I searched and found out that their thumbnails was not generated within the /uploads folder and therefore the plugin can't crop unexisting pictures.
I can upload and generate thumbnails with .png files
I can upload .jpg file but no thumbnail generated
There's no difference between small/big images size
Any idea ?