Changing a user is easy in todo4teams. You click on a user in the overview and the dialog for changing a user opens immediately. There you make the appropriate changes and press “Save”: The mandatory fields

• Username
• First name
• Last name

Are marked with a red star. If a mandatory field is invalid (e.g. if you delete the user name), it is highlighted in red and the "Save" button is deactivated so that the user cannot be saved in an inconsistent state:

If you have made changes and have not yet saved them, todo4teams will ask you whether you want to save or discard the changes so that changes are not accidentally lost: