Couldn't create dynamic image () in /var/www/customers/a0200000/www.soderbergagentur.com/html/images/gallery/821x557.
Command:
/usr/bin/convert -size 821x557 '/var/www/customers/a0200000/www.soderbergagentur.com/html/images/gallery/' -resize 821x557 -quality 90 +profile '*'  '/var/www/customers/a0200000/www.soderbergagentur.com/html/images/gallery/821x557/.jpg' 2>&1

Response:
convert: no encode delegate for this image format `/var/www/customers/a0200000/www.soderbergagentur.com/html/images/gallery/821x557/.jpg'.