Open an empty component, add a jucer component (already created apart), save component
Click on edit jucer subcomponent> a new window opens to edit the subcomponent.
Modify in any way this subcomponent and save it
Close the subcomponent.
The introjucer shows again the parent component but crashes after a few seconds.
Another thing that I find particularly annoying from the Introjucer is that when you edit a Component and set those clases it is supposed to be inheriting from, if you omit Component, it will be added automatically. This is annoying because sometimes (e.g. in plugins) you want to inherit directly from an AudioProcessordEditor or another parent class which already includes Component, creating thus a conflict.
Finally, it would be great to have a few hints somewhere on how to add new custom widgets to the Component editor. It would be really handy!
Regarding the inheritance problems, I would suggest to change component inheritance to virtual by default;
this way, inheriting multiple times from the same component will cleanly resolve to inheriting from the same
base class only once.
I think I've sorted out the inheritance thing now, but couldn't reproduce the crash. Maybe something else fixed it indirectly, or there's something particular about the files you're using?