1- Open advanced system:
Settings > Options > Application > Misc ... check box "Advanced permissions system" > OK
2- Set permissions:
Permissions > Server Groups > ..select your server group... > Client > ... select show names... >
i_client_max_clones_uid
i_client_max_clones_ip
i_client_max_clones_hwid
value= # (This value defines the max number of additional connections from the same client identity. -1 for unlimited)
Edit these conditions for groups that are experiencing problems