Cannot use SSH with old system accounts after Installation

For all SSH accounts created with DirectAdmin, it adds the “AllowUsers” option to the /etc/ssh/sshd_config file.  When DirectAdmin is installed, it will add “root” and “admin” to that file under the AllowUsers option.  Any other users who have had SSH account on the system will also require to be added to that file in order to access the server via SSH.

*IMPORTANT: For systems who require the use of “su” to access the root account, but do not use “admin” to do it, that usename *must* be added to the /etc/ssh/sshd_config before logging out or else they will not be able to login and and turn won’t be able to su to root any longer.   This isn’t as relevant for RedHat systems, because the default is to enable root login, but for most FreeBSD systems, su is required, and the starting use *must* be in the wheel group, which a newly created “admin” would not be.