HELP FILE

Why is my LastPass Vault blank when I log in offline using YubiKey authentication?

If you have multiple YubiKeys enabled for your LastPass account, only the YubiKey in Slot 1 can be used to access your Vault in offline mode. If you use another YubiKey in Slot 1, the contents of your LastPass Vault will be blank as it is not the authentication method that is used to doubly encrypted your Vault data.

Related

Use YubiKey Multifactor Authentication