Hi PhroZenOne
What seems to happen is that nativization replaces the custom thunk with the code declared in the FCustomThunkTemplates struct.
That’s right.
FCustomThunkTemplates is not intendet to be used outside the engine, so we don’t support it in nativization (yet).
The GeneratedCodeHelpers.h file is included only in nativized code, so you can modify it (without risk of breaking the actual engine code). As a workaround you can add FCustomThunkTemplates::JsonToStruct funtion (and include a proper header).
If the plugin/module containing the header is not automatically included by NativeAssets module, then add “+AdditionalPublicDependencyModuleNames=” in [BlueprintNativizationSettings] in your DefaultEditor.ini.