Invited users cannot be found when accepting an invitation

I have been unable to get users to join our Rhino Team. They are getting this message

This is the message that they get when trying to accept the invitation
There account cannot be found. Any ideas?

David

They need to create an account with the email.

It looks like you sent a Team Invite, but the recipient has not completed the steps in that email.

Do they need to create a Rhino Account first?

David

The email they receive will look like this

Got it! Thank you!!!

Yes. An account is required before someone can accept a Team invitation.