Set the build configuration to Debug/圆4 (does not make a difference, but let's all stay on the same page) Make sure Enable Just My Codeis off under Options -> Debugging -> General. Setup: (I do apologize for this being rather long.)Ĭreate a Visual Studio 2019 Example MFC Application Project (SDI App) I'm looking for a workaround or at least acknowledgement of my analysis. Stepping through MFC header code when entered via disassembly works, but setting brealpoints does not work. TL DR: Debuigging into MFC ( CString) header code does not work on both my machines and as far as I can tell this is due to the peculiar way these headers are compiled.