How to fix Scrolling issue when using Nice Scroll

We are using Magnific-Popup to display the modifiers panel, and recently we found there is an issue with the jQuery plugin Nice Scroll that prevent the scroll on the modifiers Panel, so to fix that please add the following code into Custom CSS

.white-popup {
max-height: 600px;
overflow-y: scroll;

This code will add a scroll bar into the modifiers panel and fix the height in 600px, also you can customize this height by changing the value in the code above