... is such a frustration process! After entered ID, email and password (6+ digits with at least 1 alphabet), got an error message says 'JSON could not be serialized because of error: The data couldn't be read because it isn't in the correct format' And the message flash through so quickly.. after I finally be able to capture the message.. have no idea what that means...After tired a few things.. still can't regist.. such a terrible design!