image.php & php7

Hello,
just one info: on my OVH's web hosting, if I active PHP7, the clic image link (and loop) to go next image in "single image page" of a "wordpress gallery" is broken. The result is always the same link, not the next image link...
Ok with PHP5.6, bug only with PHP7

Now I use the php script from twentyfourteen theme.

Thanks