I managed to do something catastrophically stupid and below rookie level.
Clean install on my FreeBSD VPS, then upgraded to version 9.1 (from 9). For some unusual reason, rather than installing screen first, I installed bash through pkg.
Then I changed the shell for both my user AND root. Now when I tried to log back in, on both accounts, and they are the only two accounts, I get a strange error that my google-fu has not been able to procure an answer. I get "/usr/local/bin/bash: Undefined symbol "_ThreadRuneLocale"% " after typing in the password and the. I get booted off the server. I tried doing the same through the console.
Now that I've managed to lock myself out of my account as well as root, genius that I am, I'm wondering if there's a way to login with a different shell but bypassing this problem.
When I try ssh @ -i /bin/sh .. still no go, it gives me the exact same error.