Checkbox and save button in multiselect changed in 4.5.7

We found a solution for that bug. We will fix it globally in next release. But if you need that for now, you have to do that steps.
- Go to your MDB PRO pack and find a material-select.js file.
- Next step you have to add new code. Find wrong code(160/171 line) and replace that code with this code:

options.append($('<li class="' + disabledClass + '"><img alt="" src="' + icon_url + '"' + classString + '/><span class="filtrable"><input class="form-check-input" type="checkbox"' + disabledClass + '/><label></label>' + option.html() + '</span></li>')); 

and 

options.append($('<li class="' + disabledClass + '"><span class="filtrable"><input class="form-check-input" type="checkbox"' + disabledClass + '/><label</label>' + option.html() + '</span></li>'));

- Next step you have to add function what will initiate a save button:
- Find a variable var saveSelect = $select.parent().find('button.btn-save');'
- Below that variable paste that code:

 var setSaveOption = function setSaveOption() {
     options.append(saveSelect);
   };

And the last step:
- find code saveSelect.on('click', function () {
a below that code paste that code:
setSaveOption();
And that's it. If you have any probles and question I'm here to help you.
Best,
Piotr