please help crash report :(

[jcee 0]

2015.9.6 22:00:20
OS : Windows7(32) 6.1 (Build: 7600)
CPU : AuthenticAMD  AMD Sempron(tm) 140 Processor @ 2703 MHz 1791MB RAM
Video : NVIDIA GeForce 8200 (3221)
PosCode : LS1(268) 0:0:0 1/0 [301]

Assertion failed: InPos<=Size [File:..\..\Core\Inc\FFileManagerWindows.h] [Line: 186]

History: FArchiveFileReader::Seek <- ULinkerLoad::Seek <- LoadImportMap <- ULinkerLoad::Load <- ULinkerLoad::ULinkerLoad <- UObject::GetPackageLinker <- UObject::StaticLoadObject <- (Engine.Texture L2UI_ct1.ChatBalloon.ChatBalloon_Df_TopLeft NULL) <- UCanvas::UCanvas <- UViewport::UViewport <- UWindowsClient::NewViewport <- UGameEngine::OpenInitialViewport <- UGameEngine::Init <- InitEngine