Server Server not visible on Lan Tab

[Jona]

I'm trying to host a killing floor 2 server for a lan party and
the issue i'm having is that the server isn't listed on the lan tab (I previously posted this on the killingfloor subreddit https://www.reddit.com/r/killingfloor/comments/3zzcxu/killing_floor_2_dedicated_server_not_visible/), i can connect to it just fine through the console (open <ip>) but it refuses to show up on the server browser.

The only thing that stands out to me from the logs is

    [0013.55] DevLobby: LobbyJoinGame ServerIP=

apparently the server's IP isn't assigned to the ServerIP variable in LobbyJoinGame...
is there any way to assign that manually through either the server console or through any other configuration? i've browsed through the wiki and i haven't seen anything related to it.


Things to note:

• I have updated the game and when i run "app_update 232130" it calls out saying that the app is up to date.
• I'm running the game on a separate machine in my network. (i can ping to it and i can actually connect to the server using console commands as stated previously)
• PC acting as server is running on windows 8
• I've done a clean install of steamcmd and downloaded the server overnight, it's still not showing up.
• I have validated my server files ( "app_update 232130 validate" )
• I have deleted steamapps folder and then forced validation once more (no results)
• I've turned off windows firewall

Here's the latest server log

Spoiler!

Log: Log file open, 01/08/16 08:17:28
Init: WinSock: version 1.1 (2.2), MaxSocks=32767, MaxUdp=65467
DevConfig: GConfig::LoadFile associated file: ..\..\KFGame\Config\KFLightmass.ini
DevConfig: GConfig::LoadFile associated file: ..\..\KFGame\Config\PCServer-KFUI.ini
DevConfig: GConfig::LoadFile associated file: ..\..\KFGame\Config\PCServer-KFGameStats.ini
DevConfig: GConfig::LoadFile associated file: ..\..\KFGame\Config\PCServer-KFBenchmarking.ini
DevConfig: GConfig::Find has loaded file: ..\..\Engine\Config\ConsoleVariables.ini
Init: Version: 10897
Init: Epic Internal: 0
Init: Compiled (64-bit): Jan 6 2016 19:23:21
Init: Changelist: 1532151
Init: Command line: SERVER kf-bioticslab?adminpassword=123
Init: Base directory: D:\Dedicated Apps\steamcmd\kf2server\Binaries\win64\
[0000.39] Init: Computer: NEXUS
[0000.39] Init: User: DungeonMaster
[0000.39] Init: CPU Page size=4096, Processors=4
[0000.39] Init: High frequency timer resolution =2.078121 MHz
[0000.39] Init: Memory total: Physical=5.8GB (5GB approx) Pagefile=11.8GB Virtual=8192.0GB
[0000.39] Log: Steam Client API not initialized (not required for servers)
[0000.39] Log: Automatically setting Steam query port to 27015 (server port is 7777)
[0000.39] Log: Automatically setting Steam port to 20560 (server port is 7777)
[0000.78] Log: Steam Game Server API initialized 1
[0000.78] DevOnline: appSteamInit: Steam Game Server UID: 0
[0000.78] Init: Presizing for 0 objects not considered by GC, pre-allocating 0 bytes.
[0000.79] Init: Object subsystem initialized
[0000.79] Warning: Warning, Unknown language extension . Defaulting to INT
[0000.84] Log: CachePaths() took 0.05 Seconds
[0000.85] Log: Shader platform (RHI): PC-D3D-SM5
[0003.31] Log: PhysXLevel : 0

[0004.13] Log: Executing Class Engine.ServerCommandlet
[0012.64] Log: Initializing Game Engine...
[0021.46] Warning: Warning, Failed to load 'Texture2D FX_GORE_TEX.FX_Gore_Blend_All_D': Failed to find object 'Texture2D FX_GORE_TEX.FX_Gore_Blend_All_D'
[0021.46] Warning: Warning, The Outer object (Package ENG_EngineResources_TEX.Dither) for 'ENG_EngineResources_TEX.Dither.dither_pattern' couldn't be loaded [while loading package ENG_EngineResources_TEX]: Invalid linker index [couldn't load Package ENG_EngineResources_TEX.Dither]?
[0021.46] Warning: Warning, Failed to load 'Texture2D ENG_EngineResources_TEX.Dither.dither_pattern': Failed to find object 'Texture2D ENG_EngineResources_TEX.Dither.dither_pattern'
[0027.82] Warning: Invalid movie stream data for TextureMovie UI_Managers.MenuBG
[0029.10] Log: Steam Client API is unavailable (not required for servers)
[0029.14] Log: LoadMap: kf-bioticslab?Name=Player?Team=255?adminpassword=123
[0073.79] Log: Game class is 'KFGameInfo_Survival'
[0073.86] Log: NetMode is now 1
[0074.33] Log: Bringing World KF-BioticsLab.TheWorld up for play (30) at 2016.01.08-08.18.42
[0074.34] Log: Initializing Steam game server
[0074.51] DevLobby: LobbyJoinGame ServerIP=
[0074.56] Log: Attempting to update workshop files before logging in.
[0074.76] ScriptLog: Recording game events with KFGameplayEventsWriter
[0074.76] ScriptLog: Webserver is not enabled. Set bEnabled to True in Advanced Options.
[0074.76] ScriptLog: Destroying WebServer
[0074.78] Log: Bringing up level for play took: 0.915873
[0074.78] Log: ########### Finished loading level: 45.636756 seconds
[0074.78] Log: KF2 VERSION 1021
[0074.78] Log: Initializing Game Engine Completed
[0076.30] Log: Steam game server UID: 90098869180384265
[1592.74] Log:
[1592.74] Log: Warning/Error Summary
[1592.74] Log: ---------------------
[1592.74] Log: Warning, Failed to load 'Texture2D FX_GORE_TEX.FX_Gore_Blend_All_D': Failed to find object 'Texture2D FX_GORE_TEX.FX_Gore_Blend_All_D'
[1592.74] Log: Warning, The Outer object (Package ENG_EngineResources_TEX.Dither) for 'ENG_EngineResources_TEX.Dither.dither_pattern' couldn't be loaded [while loading package ENG_EngineResources_TEX]: Invalid linker index [couldn't load Package ENG_EngineResources_TEX.Dither]?
[1592.74] Log: Warning, Failed to load 'Texture2D ENG_EngineResources_TEX.Dither.dither_pattern': Failed to find object 'Texture2D ENG_EngineResources_TEX.Dither.dither_pattern'
[1592.74] Log:
[1592.74] Log: Success - 0 error(s), 3 warning(s)
[1592.74] Log:
Execution of commandlet took: 1517.96 seconds
[1592.83] Exit: Preparing to exit.
[1593.40] Exit: Game engine shut down
[1593.49] Exit: IpNetDriverSteamworks_0 shut down
[1593.77] Exit: Object subsystem successfully closed.
[1594.29] Exit: Exiting.
[1594.29] Log: Log file closed, 01/08/16 08:44:02

Any help or hint would be greatly appreciated.

Update

Turns out the problem was on some of my client PCs. If you have virtualbox (or any other program that has its own network adapter), disabling the adapter actually makes the server show on the browser.