I spent two days also and failed to fix the issue. So I deleted the whole engine and install it through Epic Games Launcher. And 4.26.2 version to be safe. Now I will be able to release the game…although I got a few gray hair in the process. 
Indeed it seems like the SDK needs to be upgraded to fix this issue for me. But you may also need to remove the old SDK. For me it kept trying to build with 10.0.16299 even though I had 10.0.20348 installed. So I uninstalled 10.0.16299, then I regenerated the project files and rebuilt. Its happy now!
1 Like
I had the WINAPI_PARTITION_GAMES not defined error and now the editor compiles fine.
I did what you just suggested: Install the Windows 10 SDK 10.0.20348.0, and remove any other installed versions. After restarting the PC, follow again the steps to compile the source code from scrath. That means, the project as downloaded from the repository without any extra/temporary file. (I have Visual Studio Community 2019 also updated). Needless to say that I already did the installation of “NuGet Package Manger” through the Visual Studio installer.
I still have compiler errors when building the solution. This is the first one:
[54/115] Module.HeadlessChaos.4_of_5.cpp
C:/Users/Juande/Documents/UnrealEngine/Engine/Source/Programs/HeadlessChaos/Private/HeadlessChaosTestPhysicsScene.cpp(1377): error C2664: ‘void FChaosEngineInterface::CreateActor(const FActorCreationParams &,FPhysicsActorHandle &)’: cannot convert argument 2 from ‘Chaos::TGeometryParticle<float,3> *’ to ‘FPhysicsActorHandle &’
C:\Users\Juande\Documents\UnrealEngine\Engine\Source\Runtime\PhysicsCore\Public\Chaos/ChaosEngineInterface.h(333): note: see declaration of ‘FChaosEngineInterface::CreateActor’
C:/Users/Juande/Documents/UnrealEngine/Engine/Source/Programs/HeadlessChaos/Private/HeadlessChaosTestPhysicsScene.cpp(1395): error C2664: ‘void FChaosScene::AddActorsToScene_AssumesLocked(TArray<FSingleParticlePhysicsProxy *,FDefaultAllocator> &,const bool)’: cannot convert argument 1 from ‘TArray<Chaos::FGeometryParticle *,FDefaultAllocator>’ to ‘TArray<FSingleParticlePhysicsProxy *,FDefaultAllocator> &’
C:\Users\Juande\Documents\UnrealEngine\Engine\Source\Runtime\PhysicsCore\Public\Chaos/ChaosScene.h(108): note: see declaration of ‘FChaosScene::AddActorsToScene_AssumesLocked’
I still have compiler errors when building the solution. This is the first one:
Looks like you now have the same issue with the Chaos stuff that we’re all running into over here.
I was able to build (finally) following all those steps from AnserHub and:
1- For my previous builds i was using Rider then i realized that for 4.27 Rider buil the entire solution.
2- Switch to visual studio 2019, In the Solution Tree right click on UE4 and select as active project.
3- Right click on UE4 again and select Rebuild All.
Then it finish ok.
After this i was able to keep working with my othe projects using rider
in file d3d12.h
change:
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_GAMES)
to:
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) /* | WINAPI_PARTITION_GAMES)*/
Have you even been able to build the Programs\UnrealFileServer project? Or are you just building the main engine’s UE4 solution?
OK thanks. Would you mind trying to build the UnrealFileServer project? I’m curious to see how big of an issue there is with that. I’ve found a couple of people so far who have it.
1 Like
Im working in a project that needs a dedicated server. The projects started in 4.26, and back then i just click build solution (from Rider) and everything was done, no problem. Then i moved to 4.27 and i had the problems reported about chaos headers, then tried VS build solution and same.
Sadly build the engine takes a lot of time and i cannot experiment much because i must move forward with the project
FYI the HeadlessChaos issue with the new failing physics scene test is fixed in the 4.27 branch (to be released with 4.27.1). If you want to get that early you can pull in the latest from the “4.27” branch.
1 Like
That did the trick. Many thanks. 
This is fixed on 1.27.1 btw. They removed the WINAPI_PARTITION_GAMES text from the d3d12.h file
I could safely remove my change
Hi.
I use the latest Visual Studio 2022 and I ran into the same issue very recently. I surfed online for hours and after combining different solutions, I was able to bypass the issue. I hope the following steps (in any order) would be of help.
-
Open Visual Studio. Go to Tools->Options->Projects and Solutions->VC++ Project Settings
Set “Show Environment in Log” to Yes. -
Go to Tools->Options->Projects and Solutions->Build And Run
Set “MSBuild Project build output verbosity” to Diagnostic. -
Open Visual Studio Installer. Go to Modify->Individual components->Code Tools.
Here check and install NuGet package manager and NuGet targets and build tasks.
If you’re also a C#.net/.netCore (MVC) developer, you must have installed NuGet package manager along the way but confirm that NuGet targets and and build tasks are installed.
- Close Visual Studio and Unreal Engine. Restart your PC, and run again. The issue should be solved.
Please share this solution
I have the same issue, it should be introduced by commit 46c08f507c934a376be8c2f2829d1f01eb72bcaa. The hack way to fix it to revert update to NetworkFileSystem files(only several files and lines)
the commit introduces “Engine" module depency to module NetworkFileSystem used by UnrealFileServer, but UnrealFileServer should be designed not to depend on module “Engine”
I think it is a shame for Epic guys, it breaks build for such a long time on the best tested “release” branch.
2 Likes
For those of us struggling with this:
I would also suggest to remove HeadlessChaosPerf project as well on 4.27.2
1 Like