Register isn't working

Can you elaborate please? what to mean by “the register”? And in what way isn’t it working?

I don’t have, i was using the normal WP registration page on my site i.e site.com/register, but it has just vanished and I can’t seem to fix the problem as I need users to be able to register to my site asap as I run an article submission site. I was wondering is their any plugins available to let users register?

Site url?

https://ypim.co.uk/register/

Try https://ypim.co.uk/wp-login.php?action=register