Moved to MTA:SA Server problems.
To log in from the game, make sure you have 'Admin ' set up properly in the .conf file, and log in using the same name and password (rcon_login ).
For logging in with the admin client, put your local IP in the IP field (or the same one you use to connect to your server in quick connect), and make sure that the port isn't the server port, but the AdminPort specified in the .conf file (default AdminPort 44003).