Can't #include PaperFlipbookActor.h

I’m having these errors come up every time I try to extend PaperFlipbookActor. I’ve also tried extending Actor and including the PaperFlipbookComponent.h with the same errors. I tried opening the C++ example for the paper2d side scroller, in which the code extends PaperCharacter, and that compiles without any problems.

[edit]
I have added “Paper2D” module to my Build.cs file, and I’m still seeing the same error (cannot find PaperFlipbookActor.h). It spits this error out:

Error 1 error LNK2001: unresolved
external symbol "public: virtual bool
__cdecl APaperFlipbookActor::GetReferencedContentObjects(class
TArray FDefaultAllocator> &)const "
(?GetReferencedContentObjects@APaperFlipbookActor@@UEBA_NAEAV?$TArray@PEAVUObject@@VFDefaultAllocator@@@@@Z) E:\Unreal\IAT_Final\Intermediate\ProjectFiles\VerticalFlipbook.cpp.obj IAT_Final

Could it be related to this issue? Paper2D: Can't compile PaperSpriteActor - C++ - Unreal Engine Forums