experienced a ykman failure, and workaround

howto/yubikey.md

@@ -714,6 +714,9 @@ example:
     Authentication key      Cached
     Attestation key         Off
 
+If you get an error running the `info` command, maybe try to
+disconnect and reconnect the YubiKey.
+
 The default is to not require touch confirmations.
 
 Do note that touch confirmation is a little counter-intuitive: the