Hi, today, as you can see on graph http://www.gametracker.com/server_info/93.190.206.4:25565/ my server marked as dead, but it is working, people playing and no plugins or configs changed last day. I tried to rescan it, but it didn't help. Please, make my server visible.

Are people who are currently able to play on your server playing from the Internet or your local network? If they are playing from your local network then there maybe some problem with your server's connection to the internet. Check that is your server connected to the internet, also check your firewall to see if it is blocking internet access to the server.
If they are playing from the Internet then your server has connection to the internet and the problem maybe with GameTracker's scanning program. For that a GameTracker Admin can only help.

Hello,

I am unable to scan your Minecraft server. GT Minecraft services are working properly. The following thread has information on how GT scans minecraft servers: http://www.gametracker.com/games/minecraft/forum.php?thread=58741

Please double check to make sure that your config is setup correctly. You may have recently changed your server's firewall or networking configuration - this can also cause your server to stop scanning.

Best regards.

I restarted the server, rescan it on gametracker and now it visible