I tried altering the PHP, as instructed. Guess I was doing something wrong ’cause everytime I changed the PHP file, it will display an error code in the browser, preventing the site to load. Funny thing is that, even on reinstalling the old file, the site will still be down.
I decided then to just add the gallery into a post and not as a widget.
Looking forward for the next version. Customizable social network icons, maybe?
Thank you so much for your generous help!