Hello chrisdw,
Depends on whether they're on there because you blocked them, or new users are not allowed to be registered automatically, or if it's a lockout policy triggered temporary lockout. In the first case, remove the 'deny' checkbox on their account in User Permissions or Group Permissions depending on where you set the deny flag. In the second case, enable the ability for external user registration in Authentication > Settings in the Admin UI (on older versions it was a flag at the bottom of user permissions page to allow users to be added automatically if their login on an external authentication system was successful). In the third case, follow the instructions here or wait until the lockout times out;
https://openvpn.net/faq/how-do-i-unlock-users-that-are-locked-out-now/
Kind regards,
Johan
