Membership WPML Registration form does not work in second language

I will try to be as clear as possible.
I have a problem with my registration form in my second language.

I have the page /register/ set into membership option as my
Registration page with Original Membership form.

In english "first language" everything work perfectly.
In french /fr/register/ the page was all white. So in paste the shorcode [subscriptionform] in the french version.

The form load and I can chose the subscription Plan I want.
After I'm forward to a from where i fill my first name, last name, User, email password and confirm pass.
When I press the "Register My Account" the site loop back at the same page.

In chrome I look at the code and I see that the form action look like this.
action = ""

Any idea why user can't register in second language.