Compiler errors that I can't make any sense

[Angelhelm]

D:\Epic Games\UE_4.26\Unreal Training\ToonTanks\Binaries\Win64\UE4Editor-ToonTanks-9946.dll : fatal error LNK1120: 3 unresolved externals
     Creating library D:\Epic Games\UE_4.26\Unreal Training\ToonTanks\Intermediate\Build\Win64\UE4Editor\Development\ToonTanks\UE4Editor-ToonTanks-9946.suppressed.lib and object D:\Epic Games\UE_4.26\Unreal Training\ToonTanks\Intermediate\Build\Win64\UE4Editor\Development\ToonTanks\UE4Editor-ToonTanks-9946.suppressed.exp
  HealthComponent.cpp.obj : error LNK2019: unresolved external symbol "private: static class UClass * __cdecl UHealthComponent::GetPrivateStaticClass(void)" (?GetPrivateStaticClass@UHealthComponent@@CAPEAVUClass@@XZ) referenced in function "public: static void * __cdecl UHealthComponent::operator new(unsigned __int64,enum EInternal,class UObject *,class FName,enum EObjectFlags)" (??2UHealthComponent@@SAPEAX_KW4EInternal@@PEAVUObject@@VFName@@W4EObjectFlags@@@Z)
  HealthComponent.cpp.obj : error LNK2019: unresolved external symbol "public: __cdecl UHealthComponent::UHealthComponent(class FVTableHelper &)" (??0UHealthComponent@@QEAA@AEAVFVTableHelper@@@Z) referenced in function "public: static class UObject * __cdecl UHealthComponent::__VTableCtorCaller(class FVTableHelper &)" (?__VTableCtorCaller@UHealthComponent@@SAPEAVUObject@@AEAVFVTableHelper@@@Z)
  HealthComponent.cpp.obj : error LNK2001: unresolved external symbol "protected: virtual void __cdecl UHealthComponent::BeginPlay(void)" (?BeginPlay@UHealthComponent@@MEAAXXZ)

My compiler gives this error

I thought I had a made a mistake so I grabbed the github code submits to make sure their is no typos.

Any idea what might be causing this?

[Angelhelm]

I unfortunately in trying to fix this have now bricked my editor it now crashes every time I try to load unreal. Any suggestions on how I can try and compile without being in the editor?

[Angelhelm]

I was able to force the recompile by deleting all the .dll and .pdb files I reverted my code back to the previous lecture using the github and that has unblocked me.