KF Critical Error!

I recently updated my graphics card ( ATI Mobility Radeon HD5470 512MB ) and when I try to launch Killing Floor I keep getting this message:



Build UT2004_Build_[2004-11-11_10.48]



OS: Windows NT 6.1 (Build: 7601)

CPU: GenuineIntel PentiumPro-class processor @ 2261 MHz with 2996MB RAM

Video: No Video



Can't find 'ini:Engine.Engine.GameEngine' in configuration file



History: UObject::SafeLoadError <- UObject::StaticLoadClass <- InitEngine <- FMallocWindows::Free <- FMallocWindows::Realloc <- 6C52CDC0 0 FArray <- FArray::Realloc <- 0*2 <- FMallocWindows::Free <- FMallocWindows::Free













I tried reinstalling the game , verify game of cache but still ! This error comes up! ( other games launch normal )