Unreal enging crash at launch

Hello, I have problem, because when i launch my Unreal Engine it is crashing. It’s similiar to problems people have with it but it’s not about light but about “WorldGridMaterial”

Here’s the crash raport:
MachineId:0A1B410047FA3B9A2A9499BE741E068F
EpicAccountId:c0b48845c81a4d70919154aa5ec3c664

Unknown exception - code 00000001 (first/second chance not available)

"Fatal error: [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.9\Engine\Source\Runtime\Engine\Private\Materials\MaterialShared.cpp] [Line: 1393] 
Failed to compile default material WorldGridMaterial!
"

UE4Editor_Core!FDebug::AssertFailed() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\misc\outputdevice.cpp:354]
UE4Editor_Engine!FMaterial::CacheShaders() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\materials\materialshared.cpp:1393]
UE4Editor_Engine!FMaterial::CacheShaders() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\materials\materialshared.cpp:1289]
UE4Editor_Engine!UMaterial::CacheShadersForResources() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\materials\material.cpp:1839]
UE4Editor_Engine!UMaterial::CacheResourceShadersForRendering() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\materials\material.cpp:1757]
UE4Editor_Engine!UMaterial::PostLoad() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\materials\material.cpp:2371]
UE4Editor_CoreUObject!UObject::ConditionalPostLoad() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\obj.cpp:723]
UE4Editor_Engine!UMaterialInterface::PostLoadDefaultMaterials() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\materials\material.cpp:386]
UE4Editor_Engine!UMaterial::PostLoad() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\materials\material.cpp:2220]
UE4Editor_CoreUObject!UObject::ConditionalPostLoad() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\obj.cpp:723]
UE4Editor_CoreUObject!EndLoad() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1285]
UE4Editor_CoreUObject!LoadPackageInternal() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1041]
UE4Editor_CoreUObject!ResolveName() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:680]
UE4Editor_CoreUObject!StaticLoadObjectInternal() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:767]
UE4Editor_CoreUObject!StaticLoadObject() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:831]
UE4Editor_UMG!ConstructorHelpersInternal::FindOrLoadObject<UMaterialInterface>() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\public\uobject\constructorhelpers.h:32]
UE4Editor_UMG!ConstructorHelpers::FObjectFinder<UMaterialInterface>::FObjectFinder<UMaterialInterface>() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\public\uobject\constructorhelpers.h:99]
UE4Editor_UMG!UWidgetComponent::UWidgetComponent() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\umg\private\components\widgetcomponent.cpp:502]
UE4Editor_CoreUObject!UClass::CreateDefaultObject() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\class.cpp:2657]
UE4Editor_CoreUObject!UObjectLoadAllCompiledInDefaultProperties() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\uobjectbase.cpp:729]
UE4Editor_CoreUObject!ProcessNewlyLoadedUObjects() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\uobjectbase.cpp:815]
UE4Editor!FEngineLoop::PreInit() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\launchengineloop.cpp:1392]
UE4Editor!GuardedMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\launch.cpp:110]
UE4Editor!GuardedMainWrapper() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]

Hi Hohel -

Can you go into your engine installation directory under Engine Materials (usually C:\Program Files\Epic Games\4.9\EngineMaterials) and delete the WorldGridMaterial.uasset? Once deleted go into your launcher and verify the 4.9 version of the engine, which will re-download the missing uasset that you just deleted.

Try to open the engine after completing the following and let me know if you are still having issues.

Thank You

Eric Ketchum

Actually after delefing I still don’t have verify button but only launch.

In the Library the dropdown should have a verify:

59212-verify.jpg

Thank You

Eric Ketchum

Yes, now it’s working excellent! Thank You.