Link error in Custom class during the build

Development Programming & Scripting C++
1 



void ABOTRODS_V1Pawn::BeginPlay()
{
	Super::BeginPlay();

	//Custom runtime States 
	state.Add(new StateMachine(state.Num(),"BaseClass",0));   
	state.Add(new HomingMisleHit());
	state.Add(new BotCowHitBehaviour());
}

This code works fine in the editor but i get link error while building the game and all the code had be referenced properly.

UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: BOTRODS_V1Pawn.cpp.obj : error LNK2019: unresolved external symbol “public: __cdecl StateMachine::StateMachine(int,class FName,int)” (??0StateMachine@@QEAA@HVFName@@H@Z) referenced in function “public: virtual void __cdecl ABOTRODS_V1Pawn::BeginPlay(void)” (?BeginPlay@ABOTRODS_V1Pawn@@UEAAXXZ)

UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: BOTRODS_V1Pawn.cpp.obj : error LNK2019: unresolved external symbol “public: __cdecl HomingMisleHit::HomingMisleHit(void)” (??0HomingMisleHit@@QEAA@XZ) referenced in function “public: virtual void __cdecl ABOTRODS_V1Pawn::BeginPlay(void)” (?BeginPlay@ABOTRODS_V1Pawn@@UEAAXXZ)

UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: BOTRODS_V1Pawn.cpp.obj : error LNK2019: unresolved external symbol “public: __cdecl BotCowHitBehaviour::BotCowHitBehaviour(void)” (??0BotCowHitBehaviour@@QEAA@XZ) referenced in function “public: virtual void __cdecl ABOTRODS_V1Pawn::BeginPlay(void)” (?BeginPlay@ABOTRODS_V1Pawn@@UEAAXXZ)

The Destructor error
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: BOTRODS_V1Pawn.cpp.obj : error LNK2019: unresolved external symbol “public: __cdecl StateMachine::~StateMachine(void)” (??1StateMachine@@QEAA@XZ) referenced in function “public: virtual void __cdecl ABOTRODS_V1Pawn::BeginDestroy(void)” (?BeginDestroy@ABOTRODS_V1Pawn@@UEAAXXZ)