We often meet such case: I have an application with a modeless dialog. The dialog comes up perfectly in DEBUG build, But in RELEASE build, it crashed. Such problem often occures because of incorrect signature of message handle functions, that included into MFC message map for your CWnd based class.We should very carefully check signatures [...]

Here are some tips of Microsoft Visual Studio 6.0. Display the LastError’s value When we want to get the LastError message, we often using the following code. LPVOID lpMsgBuf; FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language (LPTSTR) &lpMsgBuf, 0, NULL ); // Process any inserts in lpMsgBuf. // … [...]