MODx Revolution backend browser doesn`t display thumb images

After I`m trying to put an image to my TV or whatsoever I see only empty gif images instead of thumb images. Well let me describe my problem with this image! Where is the pr开发者_开发问答oblem?

You can try to delete all the "hidden" .image.jpg images that is inside the picture folder. That way MODX will generate new thumbs.