Also, here's the crash report from UE4:
MachineId:CA744A1349A196FA02EC44A09DBC6EF1
EpicAccountId:
Access violation - code c0000005 (first/second chance not available)
""
SIG5_Project_Win32_Shipping!UMaterialInterface::InitDefaultMaterials()
SIG5_Project_Win32_Shipping!FEngineLoop::PreInit()
SIG5_Project_Win32_Shipping!GuardedMain()
SIG5_Project_Win32_Shipping!GuardedMainWrapper()
SIG5_Project_Win32_Shipping!WinMain()
SIG5_Project_Win32_Shipping!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll
ntdll