Tried these
https://multibit.org/en/help/v0.5/help_lostOrForgottenPassword.htmlDo you have old unencrypted backups?
saving-data/wallet-backup = A directory containing your encrypted wallet backups.
saving-data/wallet-unenc-backup = A directory containing your unencrypted wallet backups.
If your wallet is unencrypted then the backups are unencrypted and stored in the 'wallet-unenc-backup' directory. Then, when you add a password ALL your unencrypted backups are encrypted with your password and the old, unencrypted, copies are secure deleted.
Then all new (encrypted) backups go into the wallet-backup directory.
That way there are no unencrypted copies sat around on your disk.
