I bumped into this compiling error as creating a UUIWidget class, inheriting from UNoesisInstance.

By including NoesisInstance.h, it complains as follows:

[2/28] Compile PCH.NoesisRuntime.h
[5/28] Compile Module.UI.gen.cpp
[6/28] Compile Module.UI.cpp
[7/28] Compile UIModule.cpp
[4/28] Compile PCH.NoesisBlueprint.h
[3/28] Compile PCH.NoesisEditor.h
In file included from UEProject/Plugins/UI/Intermediate/Build/Linux/B4D820EA/UE4Editor/Development/UI/Module.UI.cpp:3:
In file included from UEProject/Plugins/UI/Source/UI/Private/UIWidget.cpp:1:
In file included from UEProject/Plugins/UI/Source/UI/Public/UIWidget.h:6:
In file included from UEProject/Plugins/NoesisGUI/Source/NoesisRuntime/Classes/NoesisInstance.h:12:
In file included from Runtime/UMG/Public/Blueprint/UserWidget.h:15:
UnrealEngine/Engine/Source/Runtime/UMG/Public/Components/Widget.h:180:1: error: declaration shadows a variable in namespace 'Noesis' [-Werror,-Wshadow]
ENUM_CLASS_FLAGS(EWidgetDesignFlags);
^
UNREAL/UnrealEngine/Engine/Source/Runtime/Core/Public/Misc/EnumClassFlags.h:14:42: note: expanded from macro 'ENUM_CLASS_FLAGS'
inline constexpr Enum operator~ (Enum E) { return (Enum)~(__underlying_type(Enum))E; }
^
UEProject/Plugins/UI/ThirdParty/NoesisSDK/Include/NsCore/Math.h:38:13: note: previous declaration is here
const float E = 2.71828182845904523536028747135266249775724709369996f;