Notice: Undefined variable: i in /gallery.php on line 51

Hi, I just set 3 columns in Options > Gallery settings > Number of columns and when visiting the gallery I now get:

Notice: Undefined variable: i in /home4/mudkings/public_html/wp-content/plugins/nextgen-gallery/view/gallery.php on line 51

I’m using NextGen version 1.9.13.

https://www.ads-software.com/extend/plugins/nextgen-gallery/