Converting online vault

I am using NS 22.7.1.32 on Win 10 1067 and wanting to revert back from an online vault to a local on my desktop pc for banking and an online vault for less important sites. Using Elsewhere’s Retaining your Local Vault thread  I pasted an empty IDDStor2.dat from my son’s pc to my required folder, re-enabled Tamper Protection, logged off the user account, back on again and even restarted the pc. Opening the vault on IE11 the vault screen is not offering Open Cloud Vault or Open Local Vault, so I presume I don't appear to have both vaults. The vault password to open is that of my online vault and not that of my son’s. Any clues please..