No me inicia ¿Qué hago?

Este es el problema que me sale:
LoginId:685f56714dcd8cfaad6ce281bec48049
EpicAccountId:355758a079d54452bf0639ce8e44a7f0

Assertion failed: [File:D:\Build++UE4\Sync\Engine\Source\Runtime\Windows\D3D11RHI\Private\D3D11Util.cpp] [Line: 249] Direct3DDevice->CreateBuffer(&Desc,pInitData,StructuredBufferResource.GetInitReference()) failed at D:\Build++UE4\Sync\Engine\Source\Runtime\Windows\D3D11RHI\Private\D3D11StructuredBuffer.cpp:77 with error E_INVALIDARG

UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_D3D11RHI
UE4Editor_D3D11RHI
UE4Editor_D3D11RHI
UE4Editor_Engine
UE4Editor_D3D11RHI
UE4Editor_D3D11RHI
UE4Editor_RHI
UE4Editor
UE4Editor
UE4Editor
UE4Editor
UE4Editor
kernel32
ntdll

Pareciera que faltan algunas referencias de Directx, intenta instalarlo nuevamente.