Use this guide when adding users, sending invitations, editing access, or deleting a user does not behave the way you expect. Most issues come down to one of three things: the permissions a user has been given, whether an invitation has been accepted, or the CAPTCHA check that protects every invite.
After reading this article you will be able to recognise the most common Users and Permissions problems by the message or behaviour you see on screen, understand why each one happens, and take the right step to resolve it.
Troubleshooting
This is by design. On the Update User sheet the email field is locked, and the Change your email link only shows a tooltip explaining the workaround. To move a user to a new email: add a new user with the new email, have them accept the invitation and join the organisation, then delete the old user once the new account works.
[!important] Existing user emails can never be edited in place. Always create the new user and confirm it can sign in before deleting the old one.