MATLAB crashes when I run MEX file

Hi, I am trying to write a mex file, When Evaluating the mex, MATLAB crashes up every time I ran it. Here is a part of C++ code that I wrote :

void mexFunction(mwSize nlhs, mxArray *plhs[],
           mwSize nrhs, const mxArray *prhs[]){   
vector<int> *NNLt;
double *NNLtout;
Vector *V;
Vector *Fb;
mwSize *sn;
mwSize nsn; 
mwSize nf; 
double hs;
double bw;
double mw; 
mwSize ncols; 
mwSize i;
double *NNLtoutt;
/* check for proper number of arguments */
if(nrhs!=9) {
  mexErrMsgIdAndTxt("MyToolbox:arrayProduct:nrhs","Nine inputs required.");
}
if(nlhs!=1) {
  mexErrMsgIdAndTxt("MyToolbox:arrayProduct:nlhs","One output required.");
}
/* get the value of the scalar input  */
nsn = mxGetScalar(prhs[4]);
nf = mxGetScalar(prhs[5]);
hs = mxGetScalar(prhs[6]);  
bw = mxGetScalar(prhs[7]);
mw = mxGetScalar(prhs[8]);
/* create a pointer to the real data in the input matrix  */
NNLt = (vector<int> *)mxGetData(prhs[0]);
V = (Vector *)mxGetData(prhs[1]);
Fb =(Vector *)mxGetData(prhs[2]);
sn = (mwSize *)mxGetData(prhs[3]); 
/* call the computational routine */    
createNNLtriangle(NNLt, V, Fb, sn, nsn, nf, hs, bw, mw);    
/* create the output matrix */
plhs[0] = mxCreateCellMatrix(nsn,50);
for(i=0;i<nsn;i++){
   mxArray* tmp = mxCreateDoubleMatrix(1, NNLt[i].size(), mxREAL);
   copy(NNLt[i].begin(), NNLt[i].end(), mxGetPr(tmp));     
   mxSetCell(plhs[0], i, tmp);
   mxFree(tmp);  
}
}

So , I am getting following errors:

This error was detected while a MEX-file was running. If the MEX-file is not an official MathWorks function, please examine its source code for errors. Please consult the External Interfaces Guide for information on debugging MEX-files.

Thanks in advance, Cheers