Getting null pointer error while interfacing between c++ and MATLAB

I am trying to interface between my c++ application and MATLAB. My IDE is visual studio '17. The initial error that I found was, my application couldn't locate the .dll (libMatlabEngine.dll, libMatlabDataArray.dll) files. So, as per the following link's suggestion ( Stack Overflow ) I've moved my .dll files to the executable folder location. This helped but my startMATLAB() is returning a NULL pointer

• Error Log: 0xC0000005: Access violation executing location 0x0000000000000000.

Could you please help me on this like where I'm going wrong?

        using namespace matlab::engine;
        using namespace matlab::data;
        unique_ptr<MATLABEngine> matlabptr = startMATLAB();
  ArrayFactory factory;
  auto inputArray = factory.createArray({ 1, 6 }, cppData.cbegin(), cppData.cend());
  auto time_array = factory.createArray({ 1, 6 }, time.cbegin(), time.cend());

[Brian Fox]

I am having the exact same issue with VS 2015 and Matlab 2019a. Would love information on this.