ssh into new jail

I have just setup a new FreeBSD jail under FreeNAS 9.10, started sshd, and enabled root login. No root password has been set, but I can't login.

What am I missing?
Check your logfiles for an error message, that should point out a possible cause.

Also keep in mind that FreeNAS is not the same as FreeBSD, so in general people won't be able to help you with that on these forums.