Not able to add new user to my wordpress website

Hi, Following a recent site migration by my host provider my site is experiencing a number of issues. The one i want to address here is that I’m unable to add a new user to the website.

I can input the new username, email and password data, and role to register the new user, but having done so, no new user is registered. And the automated email i receive as web admin referring to the new user register only shows blank data fields where it should detail username and Email.

Can someone please explain what could be causing this?

The page I need help with: [log in to see the link]