Access Violation Exception in winrt application

Question

Hi,

When i try to assign the handler retured from createfile2() to a void pointer which i passed from my application, my application is giving the following error "Unhandled exception at 0x000007F612102079 in AppToTestPlatform.exe: 0xC0000005: Access violation writing location 0x0000000000000000"

Sample code:

terror File_Open(void* fp, char *fName, eFileOpenMode aMode)
{
 HANDLE hdl = NULL;
 tError lStatus;
 // convert the string file name to LPCWSTR

    UINT a = strlen(fName);
    BSTR unicodefName = SysAllocStringLen(NULL, a);
    ::MultiByteToWideChar(CP_ACP, 0, fName, a, unicodefName, a);
    
 hdl = CreateFile2(unicodefName, GENERIC_READ, FILE_SHARE_READ, OPEN_EXISTING,0);
 lStatus = GetLastError();
 if(lStatus == ERROR_ALREADY_EXISTS || lStatus == NO_ERROR)
 {
  *fp = (tFileHandle)hdl;// Getting Error on this line   <<---
  return E_SUCCESS;
 }
}

void*handle=nullptr; 
char name[]={"C:\\Users\\win8\\AppData\\Local\\Packages\\54ed7c5f-b7d8-4842-bbf1-b6dabe9918f6_913w5jmqyr9pt\\LocalState\\Sample.txt"};//Creating a file in application local folder
int32 result=File_Open(handle, name, WRITE_MODE);

what are the possible cause for the above ?