Create an account on checkout does'nt work

Hello all,

I am from the Netherlands and my English is not very good, excuse me for that.
Just new here and well on his way with WordPress but no expert.
Years of working with “ordinary” HTML sites, but have to “learn” a new way of making sites.

Now i have a big problem.
I control for years, and now make a new site for friends, bike rental.
I use WordPress 4.4.
Woocommerce installed because it is a webshop.
http://www.rentabikehaarlem.nl/shop/

Theme: Twenty Fourteen.

I want people who place an order during check-out, the possibility to create an account, which is possible in WooCommerce. And there it goes wrong.
Order as a guest goes fine, the order comes in and is stored inside of WordPress.

But when I check thr box “Create an account?” it goes wrong.

When you do not fill in something that is neccesary the page scrolls up and you see the message you have to complete or what is wrong. That works fine.

But if I fill everything right then also scrolls the page up.
You will be given the green bar where normally it says of what is not filled in or good but there is, however, only a red circle with an ! mark.
No text with what is not entered correctly.

Tried everything, I can not get it right.

I also have the plug-in “WooCommerce Poor Guys Swiss knife” with which you can set up everything for WooCommerce.
Maybe that fly each other’s throats, so here deactivated.
Problem unfortunately not been resolved.

Help!!!!
The site is well stocked, almost all pages are ready, i have to put the products in there and I was going to throw this week the site online.
But can unfortunately not continue.

Who knows what is wrong and can help me?

Thanks huge,
Greeting,
Peter