Looks like you haven't run the auth migrations after you've upgraded?
A per-user salt has been added to increase the security of the generated password hash.
edit: please note that this is a one-way migration, once added, salts can not be removed without invalidating the password hashes. So have a backup before you migrate.
edit: migration will not regenerate the passwords, so the salt will only be added and make the hash more secure when a user changes the password and it is hashed again.