lua error playing the stalker gamemode

Hello everyone, I started a dedicated gmod server a week ago, so long i got TTT, Prop hunt, Cinema and some other awesome gamemodes running, but i seem to have problem with the stalker, i’ve tried everything i know (Wich isn’t much). My issue is the following:

I can start the server with the gamemode no problems, I can connect without any problems either but the second the game starts i get this lua error and the round doesn’t start:

gamemodes/stalker/gamemode/init.lua:145: attempt to call global 'ValidEntity' (a nil value)
  1. OnRoundStart - gamemodes/stalker/gamemode/init.lua:145
   2. RoundStart - gamemodes/fretta/gamemode/round_controller.lua:135
    3. unknown - gamemodes/fretta/gamemode/round_controller.lua:117

I don’t know that much about LUA, I had an issue with gamemodes\stalker\entities\weapons\weapon_stalker\share.lua wich i fixed by adding the correct files to the server folder, but i’m at a blind here.

I downloaded all the files from this post:

I’ve also got the files on and the workhop files

Any help is appreciated and thanks for your time.

The gamemode is outdated ( It’s for GM12 ) and will have much more error then that.
To fix this particular error, you gotta replace ValidEntity with IsValid

I just replaced EVERY SVN file manually and is working great, thanks a lot!!