Calculated fields form

When I updated to the WordPress 4.5 my Calculated fields form plugin stopped working. I have a materials calculator for my business on my website that had also stopped working and I think it is has something to do with that specific plugin. I really need my materials calculator to work due to it is crucial to my business! What do I need to do to fix this problem? Help!

My business website is https://www.yorktownmaterials.com