Linker Errors when deriving AMatineeActor

I have a bunch of matinees each for a different instance of AMyActor. When the Matinee is played for an instance of this actor, there are a few different functions that always need to be called at different points. I decided to try to derive AMyMatineeActor for AMatineeActor to add a reference to an instance of AMyActor and override NotifyEventTriggered to intercept a few events and pass them directly to AMyActor so the designers don’t have the repetitively set up the calls in the level blueprint and if something new needs to be done we don’t have to go back and change it in for hundreds of matinee instances in level blueprints.

Unfortunately, AMatineeActor in 4.3 has it’s functions spread around different files in \Engine\Source\Runtime\Engine\Private\ such as Interpolation.cpp and Replication.cpp, which don’t seem to link properly. I have tried to add this directory to my build path and the project’s build with no success. The following is some of the linker errors I get, which disappear as soon as I change AMyMatineeActor to derive from AActor instead of AMatineeActor.

1>Module.Planktos.cpp.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl AMatineeActor::GetLifetimeReplicatedProps(class TArray &)const " (?GetLifetimeReplicatedProps@AMatineeActor@@UEBAXAEAV?$TArray@VFLifetimeProperty@@VFDefaultAllocator@@@@@Z)

1>Planktos.generated.cpp.obj : error LNK2001: unresolved external symbol "public: virtual void __cdecl AMatineeActor::GetLifetimeReplicatedProps(class TArray &)const " (?GetLifetimeReplicatedProps@AMatineeActor@@UEBAXAEAV?$TArray@VFLifetimeProperty@@VFDefaultAllocator@@@@@Z)

1>Module.Planktos.cpp.obj : error LNK2001: unresolved external symbol “public: virtual void __cdecl AMatineeActor::CheckPriorityRefresh(void)” (?CheckPriorityRefresh@AMatineeActor@@UEAAXXZ)

1>Planktos.generated.cpp.obj : error LNK2001: unresolved external symbol “public: virtual void __cdecl AMatineeActor::CheckPriorityRefresh(void)” (?CheckPriorityRefresh@AMatineeActor@@UEAAXXZ)

1>Module.Planktos.cpp.obj : error LNK2001: unresolved external symbol “public: virtual void __cdecl AMatineeActor::Play(void)” (?Play@AMatineeActor@@UEAAXXZ)

1>Planktos.generated.cpp.obj : error LNK2001: unresolved external symbol “public: virtual void __cdecl AMatineeActor::Play(void)” (?Play@AMatineeActor@@UEAAXXZ)

What do I need to change/include so my project can link to these files properly? Or is there a better solution to do what I am trying to do?

Thank you for reading that wall of text.

I haven’t heard back in a while? Does this mean it isn’t possible and I shouldn’t be trying to derive from AMatineeActor?

I just hit this problem myself in Subclassing AMatineeActor and Linking Issue - Programming & Scripting - Epic Developer Community Forums.

My guess is that because of plans to rewrite Matinee, the support for exposing symbols like this is dwindling.