Sorry I do not use anti theft so guessing here
Did you want the old vault filkes restored or just to delete the vault?
Might be of help
If no go someone should popin and assist. If no help in say 2 days post back and I will ask the techs when we talk Monday
I'm also guessing here as I don't use Anti-Theft but if you temporarily turn off Access Protection in SecurityCenter it may allow you to delete that old vault.
Open SecurityCenter by double-clicking the taskbar icon
Click Navigation at top right
Click General Settings and Alerts at left
Click Access Protection to expand and disable it there.
See if the vault becomes deletable.
Don't forget to re-enable Access Protection as it stops malware from attacking McAfee's internal files.
The other thought would be to try it in Safe Mode reached by tapping F8 repeatedly at boot-up.
If either method is successful please let us know which one worked.