I have to debug a big application done in VB6. The application is comprised of a main EXE, some ActiveX projects and other ActiveX control projects.
The problem I'm facing is that I cannot hit breakpoints inside some ActiveX projects. Looks like the application is using the OCX outside the debugger because the application runs but the breakpoints are simply not there.
The main EXE has a reference set to the OCX generated by that project. If I remove that reference I get a compilation error about unknown classes.
Any help will be great.
Make sure your ActiveX project is using binary compatibility (on the Component tab of the Project Properties). If it isn't, your exe project that references the ActiveX control is pointing to a different class id than your ActiveX project and you won't be able to debug.
来源：https://stackoverflow.com/questions/3512127/can-not-debug-an-activex-inside-a-vb6-project-with-several-components-inside