When i choose the quantity just to check on my item if it works, on the cart page it doest show nothing... realy just the icon of the item no info no quantity no nothing, same happens with the menu on the mobile version i click those 3 lines and just a blank page opens... some that can help please..
Welcome to the Shopify community!
and Thanks for your Good question.
Please share your site URL,
So I will check and provide a solution here.
Do you have a backup of your theme? Try reverting back to the previous version OR download a fresh version of the theme and install it.