Killing Floor won`t start

So basically I`ve been having this issue on KF for a while now, it won`t start at all, I`ve tried to delete the .ini files like many people suggested, but to no avail. I have tried basically every possible fix on the internet but nothing works, I`ve even deleted and re-downloaded the game a couple of times but nothing works, I am aware that this is a wide spread problem on Killing Floor so i`m sitting here wondering why there is no patch to fix this problem, anyways below is the error I recieve, sometimes I get a C++ error and other times i get a critical error.

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

OS: Windows NT 6.2 (Build: 9200)
CPU: GenuineIntel PentiumPro-class processor @ 2496 MHz with 3985MB RAM
Video: Intel(R) HD Graphics 4000 (4176)

Assertion failed: Import.ClassName==NAME_Package [File:.\UnLinker.cpp] [Line: 528]

History: ULinkerLoad::VerifyImport <- ValidateImports <- ULinkerLoad::Verify <- ULinkerLoad::ULinkerLoad <- UObject::GetPackageLinker <- ULinkerLoad::VerifyImport <- ValidateImports <- ULinkerLoad::Verify <- ULinkerLoad::ULinkerLoad <- UObject::GetPackageLinker <- ULinkerLoad::VerifyImport <- ULinkerLoad::VerifyImport <- ValidateImports <- ULinkerLoad::Verify <- ULinkerLoad::ULinkerLoad <- UObject::GetPackageLinker <- UObject::StaticLoadObject <- (Engine.LevelSummary GG-VR_VerticalLowGrav.LevelSummary NULL) <- UCacheManager::ExportCacheMaps <- NewMaps <- UCacheManager::SaveNewPackages <- UCacheManager::InitCache <- UCacheManager::execInitCache <- (KFGUIController Package.KFGUIController @ Function XInterface.GUIController.InitializeController : 01BB) <- UObject::execClassContext <- (KFGUIController Package.KFGUIController @ Function XInterface.GUIController.InitializeController : 01BB) <- UObject::ProcessEvent <- (KFGUIController Package.KFGUIController, Function KFGUI.KFGUIController.InitializeController) <- UGameEngine::Init <- InitEngine <- FMallocWindows::Free <- FMallocWindows::Free

Killing Floor won`t start