[Plugin: NextGen Gallery] Homepage Slideshow Stops Working

I upgraded to WP 4.1.1 in February 2015 and ever since, my homepage slideshow & the NextGen thumbnail galleries I originally implemented on select pages with shortcode [nggallery id=X] no longer work.

After some troubleshooting, I’ve found that my HomePage slideshow will work if I disable “NextGEN Gallery by Photocrati”. But, when I do this, the NextGen Thumbnail galleries on select pages will not appear/work. On the pages w/NextGen Thumbnail Gallery, the following message appears on the page…

Fatal error: Call to undefined method Mixin::initialize() in /www/hdtheagency.com/web/home/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/nextgen_basic_gallery/package.module.nextgen_basic_gallery.php on line 414

There’s in error in code on these pages…

jQuery(document).ready(function() {
// initialize anchor tag scrolling effect (scrollTo)

I may be able to fix this by adding a $ between the parenthesis after ‘function($)’. Unsure how to edit the source code. Any advice?

Furthermore, when I do activate NextGEN Gallery by Photocrati I can only get the NextGEN Basic ImageBrowser gallery option to work on select pages. I prefer NextGEN Basic Thumbnails but it will not work. It’s much easier for clients to browse my website if the Thumbnail Gallery can be used.

Any advice on how to fix my homepage slideshow w/NextGEN Gallery by Photocrati activated AND how to fix the NextGEN Basic Thumbnails gallery for select pages?