请问大神们用MultiByteToWideChar函数后释放内存会引发中断？

最近在自学windows程序设计第6版，在第11章的例题遇到这个问题

iFileLength = MultiByteToWideChar(CP_ACP,0,(LPCCH)pText,-1,NULL,0);
pConv = new byte[iFileLength+2];
MultiByteToWideChar(CP_ACP, 0, (LPCCH)pText, -1, (PTSTR)pConv, iFileLength+1);
SetWindowText(hwndEdit, (LPCWSTR)pConv);
UpdateWindow(hwndEdit);
free(pBuffer);
free(pConv);