I'm getting an error in the console "Cannot set properties of undefined (setting 'selected')" after using this version of Select2 Multi checkboxes of wasikuss. js fiddle from the doc: https://github.com/wasikuss/select2-multi-checkboxes

I'm using 4.1.0-rc.0 version of select2 in my project: https://cdnjs.cloudflare.com/ajax/libs/select2/4.1.0-rc.0/js/select2.min.js

When i use an old version of select2 like what they're using in their js fiddle, it works. But i can't use the old version due to some reason.