Could you make UE-35937 public?
Cooking just failed and I got this call stack - mentioning this of this number.
PackagingResults: Error: === Critical error: ===
PackagingResults: Error: Assertion failed: OrderedMeshShaderMaps.Num() > 0 && bCompilationFinalized [File:D:\Build\++UE4+Release-4.19+Compile\Sync\Engine\Source\Runtime\Engine\Private\Materials\MaterialShader.cpp] [Line: 2393]
PackagingResults: Error: OrderedMeshShaderMaps.Num() is 0. bCompilationFinalized is 0. This may relate to bug UE-35937
PackagingResults: Error: [Callstack] 0x000000008407F218 KERNELBASE.dll!UnknownFunction ]
PackagingResults: Error: [Callstack] 0x0000000072427884 UE4Editor-ApplicationCore.dll!FWindowsErrorOutputDevice::Serialize() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\applicationcore\private\windows\windowserroroutputdevice.cpp:65]
PackagingResults: Error: [Callstack] 0x0000000051826D9B UE4Editor-Core.dll!FOutputDevice::LogfImpl() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:70]
PackagingResults: Error: [Callstack] 0x0000000051761949 UE4Editor-Core.dll!FDebug::AssertFailed() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:419]
PackagingResults: Error: [Callstack] 0x000000003E0EB5F2 UE4Editor-Engine.dll!FMaterialShaderMap::GetMeshShaderMap() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\materials\materialshader.cpp:2395]
PackagingResults: Error: [Callstack] 0x000000003E0FB745 UE4Editor-Engine.dll!FMaterialShaderMap::IsComplete() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\materials\materialshader.cpp:1857]
PackagingResults: Error: [Callstack] 0x000000003E0C2F85 UE4Editor-Engine.dll!FMaterial::CacheShaders() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\materials\materialshared.cpp:1676]
PackagingResults: Error: [Callstack] 0x000000003E0C3C92 UE4Editor-Engine.dll!UMaterialInstance::CacheShadersForResources() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\materials\materialinstance.cpp:2487]
PackagingResults: Error: [Callstack] 0x000000003E0C2870 UE4Editor-Engine.dll!UMaterialInstance::CacheResourceShadersForCooking() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\materials\materialinstance.cpp:2462]
PackagingResults: Error: [Callstack] 0x000000003E0C115E UE4Editor-Engine.dll!UMaterialInstance::BeginCacheForCookedPlatformData() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\materials\materialinstance.cpp:2746]
PackagingResults: Error: [Callstack] 0x000000003E102A17 UE4Editor-Engine.dll!UMaterialInstance::PostLoad() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\materials\materialinstance.cpp:3001]
PackagingResults: Error: [Callstack] 0x000000003E102D6E UE4Editor-Engine.dll!UMaterialInstanceConstant::PostLoad() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\materials\materialinstanceconstant.cpp:18]
PackagingResults: Error: [Callstack] 0x0000000053EB024D UE4Editor-CoreUObject.dll!UObject::ConditionalPostLoad() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\obj.cpp:994]
PackagingResults: Error: [Callstack] 0x0000000053F7AFAC UE4Editor-CoreUObject.dll!EndLoad() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1595]
PackagingResults: Error: [Callstack] 0x0000000053F9312B UE4Editor-CoreUObject.dll!LoadPackageInternal() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1339]
PackagingResults: Error: [Callstack] 0x0000000053F92544 UE4Editor-CoreUObject.dll!LoadPackage() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1436]
PackagingResults: Error: [Callstack] 0x000000003C003F83 UE4Editor-UnrealEd.dll!UCookOnTheFlyServer::LoadPackageForCooking() [d:\build\++ue4+release-4.19+compile\sync\engine\source\editor\unrealed\private\cookontheflyserver.cpp:2010]
PackagingResults: Error: [Callstack] 0x000000003C03B05B UE4Editor-UnrealEd.dll!UCookOnTheFlyServer::TickCookOnTheSide() [d:\build\++ue4+release-4.19+compile\sync\engine\source\editor\unrealed\private\cookontheflyserver.cpp:1619]
PackagingResults: Error: [Callstack] 0x000000003BEEA580 UE4Editor-UnrealEd.dll!UCookCommandlet::CookByTheBook() [d:\build\++ue4+release-4.19+compile\sync\engine\source\editor\unrealed\private\commandlets\cookcommandlet.cpp:904]
PackagingResults: Error: [Callstack] 0x000000003BF11CB0 UE4Editor-UnrealEd.dll!UCookCommandlet::Main() [d:\build\++ue4+release-4.19+compile\sync\engine\source\editor\unrealed\private\commandlets\cookcommandlet.cpp:584]
PackagingResults: Error: [Callstack] 0x00000000F7AFEB20 UE4Editor-Cmd.exe!FEngineLoop::PreInit() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2195]
PackagingResults: Error: [Callstack] 0x00000000F7AF69FA UE4Editor-Cmd.exe!GuardedMain() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\launch.cpp:127]
PackagingResults: Error: [Callstack] 0x00000000F7AF6C4A UE4Editor-Cmd.exe!GuardedMainWrapper() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:144]
PackagingResults: Error: [Callstack] 0x00000000F7B04177 UE4Editor-Cmd.exe!WinMain() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:223]
PackagingResults: Error: [Callstack] 0x00000000F7B04FBF UE4Editor-Cmd.exe!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253]
PackagingResults: Error: [Callstack] 0x00000000867C3034 KERNEL32.DLL!UnknownFunction ]
PackagingResults: Error: [Callstack] 0x0000000087C31551 ntdll.dll!UnknownFunction ]
PackagingResults: Error: [Callstack] 0x0000000087C31551 ntdll.dll!UnknownFunction ]