Interface.h:

#ifdef LIBRARY_EXPORTS  
#define DLLAPI __declspec(dllexport) 
#else
#define DLLAPI __declspec(dllimport)
#endif

extern "C" DLLAPI void HeatSolver();


Library.cpp:

#include "Interface.h"
#include "HeatSolver.h"

WATHANAPI void HeatSolver(){

	CHeatSolver *pHeatSolver; // Pointer to HeatSolver class
	pHeatSolver->solver();
	
}


HeatSolver.h:

class CHeatSolver{

public:	

	void solver(); // Main function of the dll

};


HeatSolver.cpp:

#include "WathunSolver.h"

void CHeatSolver::solver() { //Main function of my dll

}

Error C4700:uninitialized local variable pHeatSolver used.

WATHANAPI void HeatSolver(){

	CHeatSolver HeatSolver;
	HeatSolver.solver();
	
}