S.T.A.L.K.E.R anomaly xr_logic Crash Thread

Hello

I stumbled upon this crash while asking Sakharov for quests. On other forums it said that i have to remove hotfixes / updates from updates folder. however i dont have such files. Anyway i attached the log. Would really appreciate the solution!

FATAL ERROR

[error]Expression : <no expression>
[error]Function : CScriptEngine::lua_error
[error]File : ..\xrServerEntities\script_engine.cpp
[error]Line : 191
[error]Description : fatal error
[error]Arguments : LUA error: /gamedata\scripts\xr_logic.script:491: attempt to call a nil value

You might have to do more main missions before you can do Sakharov quest? That's what I did and never experienced crashing.