I am not sure how this is happening, but I found the area that needs to be trapped. When I have a select element with the multiple attribute. When I deselect all options, I get an error "elems is null" at line 648 of 1.4.2 non-minified version.

Here is a possible fix:

Go through the array, only saving the items

that pass the validator function

if (elems == null) return ret;

I need to make updates to the page when no options are selected and the event "change" works properly with this addon. Otherwise I get an error and the change event stops working altogether.