Yubikey Guide
GPG Errors
When GnuPG complains the the Yubikey inserted is the incorrect key for the action you're trying to take, but you know that it is the only key with the information on it that is being requested, you need to do the following:
$ gpg --list-secret-keys --with-keygrip
within the output will be listed a Key Grip ID for the encryption key (or whatever key is in error from GPG). Take that ID and go to `~/.gnupg/private-keys-v1.d` and remove the file name that matches. After that restart the GnuPG daemon and any process.