Entry Registration doesn't work

-- HikaShop version -- : 2.6.4
-- Joomla version -- : 3.4.8
-- PHP version -- : 5

I added an entry to my main menu with the item hikashop entry registration.

When I click on the entry in the menu I get a blank page.
When I do the same with registration form. This works. The user can register, but, won't get an activation email.


So, what could be the reason for not seeing Entry Registration??

Kind regards,