Email already used in a Box account but not associated with an enterprise

You just need to click the save option twice. After your first click, a red banner will appear that indicates failure. Press the save button once more and you'll get the prompt that says "1 user added". Then, the user will receive an email invitation to join the enterprise.

This doesn’t work. I clicked again and the red button is just pulsing and appears frozen. It has been like this for five minutes now.