Launcher crashes every time

I keep crashing everytime I try to launch any of my projects.

MachineId:0AE2F897437939817791A99B81CA6352
EpicAccountId:9d53679bb24d4795b8f51259eabeeeef

Fatal error: [File:D:\Build\++UE4+Release-4.12+Compile\Sync\Engine\Source\Runtime\Engine\Private\Materials\MaterialShared.cpp] [Line: 1575] 
Failed to compile default material WorldGridMaterial!


UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:440]
UE4Editor_Engine!FMaterial::CacheShaders() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\materials\materialshared.cpp:1575]
UE4Editor_Engine!FMaterial::CacheShaders() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\materials\materialshared.cpp:1469]
UE4Editor_Engine!UMaterial::CacheShadersForResources() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\materials\material.cpp:2017]
UE4Editor_Engine!UMaterial::CacheResourceShadersForRendering() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\materials\material.cpp:1935]
UE4Editor_Engine!UMaterial::PostLoad() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\materials\material.cpp:2581]
UE4Editor_CoreUObject!UObject::ConditionalPostLoad() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\obj.cpp:748]
UE4Editor_Engine!UMaterialInterface::PostLoadDefaultMaterials() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\materials\material.cpp:387]
UE4Editor_Engine!UMaterial::PostLoad() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\materials\material.cpp:2395]
UE4Editor_CoreUObject!UObject::ConditionalPostLoad() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\obj.cpp:748]
UE4Editor_CoreUObject!EndLoad() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1452]
UE4Editor_CoreUObject!LoadPackageInternal() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1171]
UE4Editor_CoreUObject!LoadPackageInternal() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1286]
UE4Editor_CoreUObject!ResolveName() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:696]
UE4Editor_CoreUObject!StaticLoadObjectInternal() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:783]
UE4Editor_CoreUObject!StaticLoadObject() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:853]
UE4Editor_UMG!ConstructorHelpersInternal::FindOrLoadObject<UMaterialInterface>() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\public\uobject\constructorhelpers.h:31]
UE4Editor_UMG!UWidgetComponent::UWidgetComponent() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\umg\private\components\widgetcomponent.cpp:462]
UE4Editor_CoreUObject!UClass::CreateDefaultObject() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:3340]
UE4Editor_CoreUObject!UObjectLoadAllCompiledInDefaultProperties() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectbase.cpp:725]
UE4Editor_CoreUObject!ProcessNewlyLoadedUObjects() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectbase.cpp:819]
UE4Editor!FEngineLoop::PreInit() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:1503]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launch.cpp:114]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll

Hello,

I’m sorry that you are having an issue with the Epic Games Launcher. In order for us to offer the best support, we have recently modified the process for how Epic Games can help troubleshoot your Launcher issue. Please visit http://help.epicgames.com/ for technical support, here you can find information and solutions for common issues, as well as a contact form if you still need additional assistance. To access the contact form, please use the “Email Us” button under the “Contact Us” section. Thanks!

Have a great day

Already tried that. Nothing there has helped…

If you need additional help, please use the “Email Us” button under the “Contact Us” section to get in touch with one of our support staff.

Thanks!