There have been a number of users here that are unable to log into Identity Safe online vault from the NIS or 360 clients. They are, however, able to log into the web site at https://identitysafe.norton.com .
My suggestion is that there be a way to backup/export the ID Safe online vault from the web site. That way, if they do not have a backup, they can now be able to do so before troubleshooting begins that may lose the data if the vault gets reset.