4.22.3 building from source raises C2338: Windows headers require the default packing option

Development Programming & Scripting
1

I built 4.22.3 from source with command

RunUAT.bat BuildGraph -target="Make Installed Build Win64" -script=Engine/Build/InstalledEngineBuild.xml -set:WithDDC=false -set:HostPlatformOnly=true

with Visual Studio 2019(16.2.3, MSVC v14.22) and Windows 10 SDK(10.0.18362.0).

And when Compile UE4Game Win32, compiler raises this error:

C:\Program Files (x86)\Windows Kits\10\include\10.0.18362.0\um\winnt.h(2482): error C2338: Windows headers require the default packing option. Changing this can lead to memory corruption. This diagnostic can be disabled by building with WINDOWS_IGNORE_PACKING_MISMATCH defined.

Can I surpress this error or should I modify source code(or is there any ideas to fix this)?

2

I found that vctoolchain of UBT forces /Zp8 on 64bit, /Zp4 on 32bit. But there’s no information about unreal should use specific memory packing. I just surressed that diagnostic error.

3

I have the same issue as well.

4

Here is the solution i found:

So, the problem is that the new Windows 10 SDK version (10.0.18362.0) has new restrictions that cause the build to fail.

I was able to successfully build it using the 10.0.16299.0 SDK. Therefore, I would recommend you to switch an earlier SDK until the issue is resolved.

You would need to change WindowsSdkVersion in Engine/Source/Programs/UnrealBuildTool/Platforms/Windows/UEBuildWindows.cs to make sure the Automation Tool uses the correct Windows SDK version.

I hope this finds you well.

Greetings,
xCocoDev

5

I have “10.0.16299.0” installed and tried these settings in UEBuildWindows.cs:


public string WindowsSdkVersion = "10.0.16299.0";

static readonly VersionNumber[] PreferredWindowsSdkVersions = new VersionNumber[]
		{
			VersionNumber.Parse("10.0.16299.0")
		};

I have deleted all Intermediate files.
Unfortunately UE 4.25 still uses “10.0.18362.0” in the generated .vcxproj and in the packaging build.

Are there other files where I can set the Windows SDK?

Greets

6

Yes. in BuildConfiguration.xml.

7

Have searched these folders for BuildConfiguration.xml:

  • Engine/Saved/UnrealBuildTool/BuildConfiguration.xml
  • User Folder/AppData/Roaming/Unreal Engine/UnrealBuildTool/BuildConfiguration.xml
  • My Documents/Unreal Engine/UnrealBuildTool/BuildConfiguration.xml*

Nowhere is the Windows SDK set.

8

Ok, its solved!
I have edit the User Folder/AppData/Roaming/Unreal Engine/UnrealBuildTool/BuildConfiguration.xml to:

<BuildConfiguration>	
</BuildConfiguration>
<WindowsPlatform>
	<WindowsSdkVersion>10.0.16299.0</WindowsSdkVersion>
</WindowsPlatform>

This changes the WindowsSdk for all user projects.
However, doing this for the project only by adding the file under my_project/config/UnrealBuildTool/BuildConfiguration.xml did not work.

Thanks very much for help. Greets

9

This is, at least for me, the working solution provided by the Unreal Support. Just add this to your main .Build.cs file:

PublicDefinitions.Add("WINDOWS_IGNORE_PACKING_MISMATCH");

Nothing else to add or modify.

Greets, solarisx

10

Hello, Can you give me The main .Build.cs FilePath, I Can’t find the file , Thanks!

11

‘your project folder\Source\project name\project name.Build.cs’
To get a .Build.cs file and a Source folder you have to make you project a c++ project or at leaste add a c++ dummy class file to your project from the unreal editor. https://docs.unrealengine.com/en-US/ProgrammingAndScripting/ProgrammingWithCPP/CPPProgrammingQuickStart/index.html

12

I meet this error when build engine from source code ,Use require WindosSDK could work, Thank you!