Plugin not working on IE and some other old browsers

Got a problem, when on newly launched client told me that can not select an option. Radio is selected, but when click “add to cart” she got that error message telling to select variant first.

I was able to get a screen-shot from her, looks like some older chrome version on mac.
Tried to test it on IE11(Windows 10) and got error:

SCRIPT1002: Syntax error
frontend.js (95,5)

Same with your demo site: https://demo.wpclever.net/woovr/product/hoodie/

 if (jQuery(state.element).attr('data-imagesrc') != '') {
    $state = jQuery(
        '<span class="image"><img src="' +
        jQuery(state.element).attr('data-imagesrc') +
        '"/></span><span class="info"><span>' + state.text + '</span> <span>' +
        jQuery(state.element).attr('data-description') + '</span></span>',
    ); // 95 line is here
  } else {

The page I need help with: [log in to see the link]