Game projects that rely on legacy include paths are not compatible with Blueprint nativization.

Using legacy-style #include paths in a game project is allowed by UBT by default, but it's currently not compatible with Blueprint nativization, as it does not account for this possibility.

Current workaround: Add the following line to the constructor in Engine\Content\Editor\Templates\PluginModule.Build.cs.template:

bLegacyPublicIncludePaths = Target.bLegacyPublicIncludePaths;

Then repeat step #8.

1. Open a new, blank C++ project.
2. Add a new C++ class derived from Actor (MyActor).
3. In the new C++ class header file (MyActor.h), add:

   #include "DateTime.h"
   

4. Compile in Visual Studio and wait for hot reload to finish.
5. Right-click the MyActor class in the Content Browser and choose "Create Blueprint class based on MyActor."
6. In the Blueprint Editor, add a new variable of any type. Compile, save and close the Blueprint editor.
7. In Edit->Project Settings->Packaging, change "Blueprint Nativization Method" to "Inclusive."
8. Choose File->Package Project->Windows->Win64, choose a location and proceed.
9. Note that a C++ compiler error will result in the Build phase after cooking has completed:

   [1/3] Module.NativizedAssets.gen.cpp
   UATHelper: Packaging (Windows (64-bit)):     D:\dev\local\Projects\CppTest\Source\CppTest/MyActor.h(6): fatal error C1083: Cannot open include file: 'DateTime.h': No such file or directory
   

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