Debug in Eclipse - ClassNotFoundException

While debugging try Step Return (F7 as shortcut) to get one level up at a time and thus out of the libs you don't have the source attached for.

After Launching Debug Mode.

Go to Window → Show View → Break Points. Now you would be able to see Break Point tab in Debugging mode.

Uncheck the option "ClassNotFoundException: caught and uncaught".

I've been having this problem for a few months now. I'd be debugging a java app and every time I'd hit a constructor, eclipse would try to find matching java core library ClassNotFoundException's source code.

I solved this problem by right-clicking in Debug window on the ClassNotFoundException when I hit it, and clicking on Filter Type. I would then right-click in the debug window again and choose Edit Step Filters.... In the Edit Step Filters window I checked everything in the Defined Step Filters section and unchecked everything in the bottom of the window (Filter synthetic methods, Filter static initializers, etc).

Hope this helps others in the future.