CSGO in offline mode doesn´t work

[| LR |Rattlesnake]

Hi @all,

we have a LANparty this Weekend and we have big Problems, playing CS:GO offline.
All Players who are in the steam Offline mode can´t connect to our dedicated server.

I have the actual Linux Dedicated Server and didn´t have any idea what´s wrong...
In my Client-Console I got the followoing error Message when they want to connect to the Dedicated Server:

Connecting to public(172.30.100.101:27015) ...
555.618: Sending UDP connect to public IP 172.30.100.101:27015
Server using 'public' lobbies, requiring pw no, lobby id 0
RememberIPAddressForLobby: lobby 0 from address 172.30.100.101:27015
Grace request retry for unreserved server...
Retrying public(172.30.100.101:27015) ...
555.635: Sending UDP connect to public IP 172.30.100.101:27015
Server using 'public' lobbies, requiring pw no, lobby id 0
RememberIPAddressForLobby: lobby 0 from address 172.30.100.101:27015
Server approved grace request...
Retrying connection to 172.30.100.101:27015, server requires lobby reservation but is unreserved.
Received game details information from 172.30.100.101:27015...
] connect 172.30.100.101:27015
Connecting to public(172.30.100.101:27015) ...
562.700: Sending UDP connect to public IP 172.30.100.101:27015
Server using 'public' lobbies, requiring pw no, lobby id 0
RememberIPAddressForLobby: lobby 0 from address 172.30.100.101:27015
Server approved grace request...
Retrying connection to 172.30.100.101:27015, server requires lobby reservation but is unreserved.
Received game details information from 172.30.100.101:27015...
CSysSessionHost: CreateSession failed. Error 3


I have started the Dedicated Servers with following Parameters:

./srcds_run -game csgo -console -usercon +game_type 0 +game_mode 0 +mapgroup mg_bomb +map de_dust -port 27015 +ip 172.30.100.101 +exec server_1.cfg -insecure -tickrate 128 +sv_lan 1
or
./srcds_run -game csgo -console -usercon +game_type 0 +game_mode 0 +mapgroup mg_bomb +map de_dust -port 27015 +ip 0.0.0.0 +exec server_1.cfg -insecure -tickrate 128 +sv_lan 1

Always the same result.

When some of the clients are online they can connect to the Server without Problems.

Has anyone a solution for this Problem?

My server.cfg is the following: http://pastebin.com/tjNVwpVL
gamemodes_server.txt: http://pastebin.com/1egWU4Wh

Please help we are realy in trouble.

Best Regards

Christoph Raible