Can't deactivate Studio licence from old PC

I have a Studio licence with two activations. One is used on my notebook; the other, in my wife's notebook.

I just bought a new desktop, so I want to deactivate the Studio licence in my wife's notebook so I can use it in my desktop. However, online deactivation doesn't work ("Could not revoke this license. - Revocation is either complete or revocation proof is already uploaded").

I've tried generating a deactivation token for offline deactivation, but then Studio gives me this: "Failed to deactivate offline. The specified deactivation authorization may not be valid. Validate your deactivation authorization against the authorization in your SDL Account".

How can I solve this?