Workaround: delete the UbuntuOne account and recreate it. Note, after deleting the UbuntuOne account, you can't create a new UbuntuOne account in System Settings/Accounts without restart System Settings/Accounts.
Workaround: delete the UbuntuOne account and recreate it. Note, after deleting the UbuntuOne account, you can't create a new UbuntuOne account in System Settings/Accounts without restart System Settings/Accounts.