.......................
	iRetCode = link (caCurrentFilename, caBackupFilename);
	if (iRetCode == -1)
	{
		ERR_MSG2(LOG_ALERT, "Can't move %s to %s", caCurrentFilename, caBackupFilename);
		return(FAILURE);
	}
	
	iRetCode = unlink (caCurrentFilename);
	if (iRetCode == -1)
	{
		ERR_MSG2(LOG_ALERT, "Can't move %s to %s", caCurrentFilename, caBackupFilename);
		return(FAILURE);
	}


	fpTFFile = fopen (caCurrentFilename, "wb"); 
	if (fpTFFile == NULL)
	{
		ERR_MSG1 (LOG_ALERT, "Can't open %s\n", caCurrentFilename);
		return (FAILURE);
	}

/*
the program crashes here while calling the fwrite function. 
I have verified all the parameters of fwrite. They are valid pointers.  I’ve also tried putting another fwrite function writing a hard coded value into a file. That function also is crashing.
I've replaced fwrite with fprintf, but still getting the same error.
*/
	if (fwrite (pCurSectData->pucData, sizeof (Uchar_t), pCurSectData->ulDataSize, fpTFFile)
		!= pCurSectData->ulDataSize)
	{
		ERR_MSG1 (LOG_ALERT, "Can't save modified TF data to %s\n", caCurrentFilename);
		return (FAILURE);
	}

             ................................

pCurSectData->pucData

sizeof (Uchar_t) * pCurSectData->ulDataSize