WooCommerce does not work properly

Hello guys and girls,

I’m currently working on a big shop system using the WooCommerce plugin, together with the following plugins:

• WooCommerce Customizer
• WooCommerce Deutsch (de_DE)
• WooCommerce PDF Invoices & Packing Slips
• WooCommerce Price by Country
• WooCommerce Video Produkt-Tab

The following problem occurred.
I’m working with grouped products and on my laptop it’s working with Google Chrome. However, Firefox and Internet Explorer won’t display any buttons, nor the product list inside a grouped product. We tried to bring all salesman to use Google Chrome for the system, but it seems like that it is not working in every Google Chrome we use. One colleague tested the system yesterday and even installed Google Chrome for it. Everything worked fine, today he can’t see any products. With “Inspect Element” I recognize that the <form class="cart" method="post" enctype="multipart/form-data"> is missing on those systems. I’ve tried another template, deleted extra lines of code, but nothing works. So I hope that you’ve had the same problems at one moment and still know how to resolve that.

Thanks in advance.